On Call® Sure GK Blood Glucose & Ketone Monitoring System; On Call® Sure Sync GK Blood Glucose & Ketone Monitoring System

K250085 · ACON Laboratories, Inc. · NBW · Oct 10, 2025 · Clinical Chemistry

Device Facts

• Record ID: K250085
• Device Name: On Call® Sure GK Blood Glucose & Ketone Monitoring System; On Call® Sure Sync GK Blood Glucose & Ketone Monitoring System
• Applicant: ACON Laboratories, Inc.
• Product Code: NBW · Clinical Chemistry
• Decision Date: Oct 10, 2025
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 862.1345
• Device Class: Class 2
• Attributes: Pediatric

Intended Use

The On Call® Sure GK Blood Glucose & Ketone Monitoring System is comprised of the On Call® Sure GK Blood Glucose & Ketone Meter, the On Call® Sure Blood Glucose Test Strips, and the On Call® Sure Blood Ketone Test Strips. The On Call® Sure GK Blood Glucose & Ketone Monitoring System is intended to quantitatively measure blood glucose or blood ketone in fresh capillary whole blood from the fingertip. The system is intended for self-testing by people with diabetes at home as an aid in monitoring the effectiveness of diabetes control program. The system is for in vitro diagnostic use. It should only be used by a single patient and should not be shared. It is not intended for diagnosis or screening of diabetes or for neonatal use. The On Call® Sure Sync GK Blood Glucose & Ketone Monitoring System is comprised of the On Call® Sure Sync GK Blood Glucose & Ketone Meter, the On Call® Sure Blood Glucose Test Strips, and the On Call® Sure Blood Ketone Test Strips. The On Call® Sure Sync GK Blood Glucose & Ketone Monitoring System is intended to quantitatively measure blood glucose or blood ketone in fresh capillary whole blood from the fingertip. The system is intended for self-testing by people with diabetes at home as an aid in monitoring the effectiveness of diabetes control program. The system is for in vitro diagnostic use. It should only be used by a single patient and should not be shared. It is not intended for diagnosis or screening of diabetes or for neonatal use.

Device Story

System uses amperometric biosensor technology to measure glucose and β-hydroxybutyrate in capillary whole blood. Input: fingerstick blood sample via capillary action into test strips containing glucose dehydrogenase-FAD or 3-hydroxybutyrate dehydrogenase. Meter measures electrical current proportional to analyte concentration; displays plasma-equivalent results. Used at home by patients with diabetes for self-monitoring. On Call® Sure Sync GK model includes Bluetooth for wireless data transmission to mobile devices; On Call® Sure GK uses USB. Output: quantitative glucose (mg/dL) or ketone (mmol/L) readings. Results aid patients in monitoring diabetes control programs. Device is for single-patient use only; requires specific disinfection protocols to prevent pathogen transmission.

Clinical Evidence

Lay user evaluation (n=101) assessed ketone measurement accuracy in intended-use environment. Results for concentrations <1.5 mmol/L: 88.7% within ±0.15 mmol/L; 97.9% within ±0.225 mmol/L; 100% within ±0.30 mmol/L. For concentrations ≥1.5 mmol/L: 100% within ±10%, ±15%, and ±20%. Supplemental study (n=53) with altered whole blood samples confirmed accuracy up to 8 mmol/L. Usability and readability assessments confirmed user satisfaction and grade 8 or lower reading level.

Technological Characteristics

Amperometric biosensor technology. Glucose strips use glucose dehydrogenase-FAD; ketone strips use 3-hydroxybutyrate dehydrogenase. Hematocrit range 10-70%. Connectivity: USB (Sure GK) or USB/Bluetooth (Sure Sync GK). Operating conditions: 5-40°C, 10-90% RH. Calibration: automatic. Sterilization: not applicable (single-use strips). Software: IEC 62304 compliant.

Indications for Use

Indicated for self-testing by people with diabetes at home to quantitatively measure blood glucose or blood ketone in fresh capillary whole blood from the fingertip. Not for diagnosis or screening of diabetes; not for neonatal use.

Regulatory Classification

Identification

A glucose test system is a device intended to measure glucose quantitatively in blood and other body fluids. Glucose measurements are used in the diagnosis and treatment of carbohydrate metabolism disorders including diabetes mellitus, neonatal hypoglycemia, and idiopathic hypoglycemia, and of pancreatic islet cell carcinoma.

Special Controls

*Classification.* Class II (special controls). The device, when it is solely intended for use as a drink to test glucose tolerance, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 862.9.

Submission Summary (Full Text)

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FDA U.S. FOOD &amp; DRUG ADMINISTRATION

October 10, 2025

ACON Laboratories, Inc.
% James Mullally
Vice President, IVD Regulatory Affairs
MCRA, an IQVIA Company
803 7th Street NW
Washington, District of Columbia 20001

Re: K250085
Trade/Device Name: On Call® Sure GK Blood Glucose and Ketone Monitoring System;
On Call® Sure Sync GK Blood Glucose and Ketone Monitoring System
Regulation Number: 21 CFR 862.1345
Regulation Name: Glucose Test System
Regulatory Class: Class II
Product Code: NBW, JIN
Dated: September 9, 2025
Received: September 10, 2025

Dear James Mullally:

We have reviewed your section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (the Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

U.S. Food &amp; Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993
www.fda.gov

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K250085 - James Mullally
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Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).

Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30, Design controls; 21 CFR 820.90, Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review, the QS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801 and Part 809); medical device reporting (reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reporting-combination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.

All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/unique-device-identification-system-udi-system.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-devices/medical-device-safety/medical-device-reporting-mdr-how-report-medical-device-problems.

For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-

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K250085 - James Mullally
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assistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email ([e-mail]) or phone [phone] or 301-796-7100).

Sincerely,

JOSHUA BALSAM -S

Joshua M. Balsam, Ph.D.
Branch Chief
Division of Chemistry and Toxicology Devices
OHT7: Office of In Vitro Diagnostics
Office of Product Evaluation and Quality
Center for Devices and Radiological Health

Enclosure

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FORM FDA 3881 (8/23)
Page 1 of 1
PSC Publishing Services [phone]
EF

| DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration Indications for Use | Form Approved: OMB No. 0910-0120 Expiration Date: 07/31/2026 See PRA Statement below. |
| --- | --- |
| 510(k) Number (if known) K250085 | |
| Device Name On Call® Sure GK Blood Glucose & Ketone Monitoring System | |
| Indications for Use (Describe) The On Call® Sure GK Blood Glucose & Ketone Monitoring System is comprised of the On Call® Sure GK Blood Glucose & Ketone Meter, the On Call® Sure Blood Glucose Test Strips, and the On Call® Sure Blood Ketone Test Strips. The On Call® Sure GK Blood Glucose & Ketone Monitoring System is intended to quantitatively measure blood glucose or blood ketone in fresh capillary whole blood from the fingertip. The system is intended for self-testing by people with diabetes at home as an aid in monitoring the effectiveness of diabetes control program. The system is for in vitro diagnostic use. It should only be used by a single patient and should not be shared. It is not intended for diagnosis or screening of diabetes or for neonatal use. | |
| Type of Use (Select one or both, as applicable) ☐ Prescription Use (Part 21 CFR 801 Subpart D) ☑ Over-The-Counter Use (21 CFR 801 Subpart C) | |
| CONTINUE ON A SEPARATE PAGE IF NEEDED. | |
| This section applies only to requirements of the Paperwork Reduction Act of 1995. *DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.* | |
| The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to: Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff [e-mail] | |
| "An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number." | |

{4}

FORM FDA 3881 (8/23)
Page 1 of 1
PSC Publishing Services [phone]
EF

| DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration Indications for Use | Form Approved: OMB No. 0910-0120 Expiration Date: 07/31/2026 See PRA Statement below. |
| --- | --- |
| 510(k) Number (if known) K250085 | |
| Device Name On Call® Sure Sync GK Blood Glucose & Ketone Monitoring System | |
| Indications for Use (Describe) The On Call® Sure Sync GK Blood Glucose & Ketone Monitoring System is comprised of the On Call® Sure Sync GK Blood Glucose & Ketone Meter, the On Call® Sure Blood Glucose Test Strips, and the On Call® Sure Blood Ketone Test Strips. The On Call® Sure Sync GK Blood Glucose & Ketone Monitoring System is intended to quantitatively measure blood glucose or blood ketone in fresh capillary whole blood from the fingertip. The system is intended for self-testing by people with diabetes at home as an aid in monitoring the effectiveness of diabetes control program. The system is for in vitro diagnostic use. It should only be used by a single patient and should not be shared. It is not intended for diagnosis or screening of diabetes or for neonatal use. | |
| Type of Use (Select one or both, as applicable) ☐ Prescription Use (Part 21 CFR 801 Subpart D) ☑ Over-The-Counter Use (21 CFR 801 Subpart C) | |
| CONTINUE ON A SEPARATE PAGE IF NEEDED. | |
| This section applies only to requirements of the Paperwork Reduction Act of 1995. *DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.* | |
| The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to: Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff [e-mail] | |
| "An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number." | |