SpotSee WarmMark QR Temperature Sensors are single-use and battery-free sensors that are enabled by smartphones. These sensors detect temperature excursions and provide data such as time, date, location, and serial number. The WarmMark QR temperature sensors offer clear indicators and change from white to pink/red when high temperatures are detected. The WarmMark QR sensors feature ±1°C temperature accuracy and a pull-tab activation method. These sensors comply with 21 CFR part 11 requirements. The WarmMark QR sensors are used in pharmaceutical shipments, medical supplies, perishable food supply chains, and temperature-sensitive cargo applications.