About Nonin Medical
Nonin Medical was founded in 1986 and designs and manufactures noninvasive patient monitoring devices for healthcare professionals and individual users. The name is short for noninvasive, and the company describes itself as the original maker of finger pulse oximeters. Its range covers fingertip, wrist-worn, handheld, and tabletop oximeters, along with sensors and software.
Our review of the Nonin TruO2 OTC Pulse Oximeter 3250 looks at the brand's over-the-counter fingertip model. It is FDA-cleared for OTC use, so no prescription is required. The 3250 uses Nonin's PureSAT signal processing, is validated across skin tones, and sends readings over Bluetooth to the NoninConnect app and Apple Health. It runs on two AAA batteries, is FSA/HSA eligible, and comes with a 2-year warranty.
Brand website: nonin.com
What Nonin Medical makes
Nonin Medical's range runs wider than the products we review. The lines we know best from our own testing are marked with a star:
Fingertip Pulse Oximeters
includes the TruO2 OTC Model 3250 we reviewed, alongside the Onyx Vantage 9590, Onyx II 9550, and NoninConnect Elite 3240 — featured on BestRatedDocs
Wrist-Worn Oximeters
the WristOx line, offered with USB and Bluetooth LE connectivity
Handheld Oximeters
includes the CO-Pilot and the PalmSAT 2500 Series
Tabletop Monitors
includes the SenSmart Model X-100 and Avant 9600
Sensors
reusable, disposable, and hybrid sensor options
Software
includes the NoninConnect app and data management tools
Why we recognized Nonin Medical
The BestRatedDocs Top Brand recognition isn't paid for and can't be applied for. We award it to the brands whose products consistently stand out in our category reviews. Nonin Medical earned it on the strength of the products below, evaluated the same way every product on this site is: assessed against clinical criteria, verified specifications, and real-world user outcomes, and judged on merit.
Nonin Medical products we rated highly
Nonin TruO2 OTC Pulse Oximeter 3250
A fingertip oximeter that is FDA-cleared for over-the-counter use and validated across skin tones. PureSAT signal processing handles the measurement, and Bluetooth sync to the NoninConnect app and Apple Health keeps a record of spot checks over time. It takes two AAA batteries, is FSA/HSA eligible, and carries a 2-year warranty.
Read the 7 Best Pulse Oximeters of 2026 guide →What earned Nonin Medical the recognition
- The TruO2 OTC 3250 is FDA-cleared for over-the-counter use, so a home user does not need a prescription.
- Our review notes that the 3250 is validated across skin tones.
- Nonin's PureSAT signal processing and Bluetooth sync to the NoninConnect app and Apple Health make the 3250 useful for tracking spot checks over time.
- The 3250 is FSA/HSA eligible and backed by a 2-year warranty.