TICKR Fit heart rate armband uses optical heart rate technology to provide accurate heart rate and calorie burn data in the most comfortable form factor yet! Equipped with Bluetooth and ANT+ technology to seamlessly pair with fitness apps, smartphones, and GPS bike computers and watches. Worn on the forearm, the TICKR Fit heart rate monitor comes with an adjustable band that is designed for your most grueling workouts including running, cycling, fitness classes, and more. TICKR Fit has water-resistant technology and a rechargeable battery that lasts up to 30 hours. Dual Band Technology Real Time Heart Rate And Calorie Tracking Advanced Performance Material USB Rechargeable Battery LED Indicator Lights Two Adjustable Bands Included Third Party App Compatibility Apple Watch And Apple TV Integration Rechargeable Battery: 30+ hours Strap Length: Small 10" x 1" (260mm x 25.4mm) and Large 15" x 1" (375mm x 25.4mm) Water Resistant: IPX7 (waterproof up to 5 feet) Sweat proof: Yes (hand washable strap) On/Off Button Not compatible with chest straps