Wahoo TICKR X Heart Rate Monitor with Memory, Bluetooth / ANT+ The battery is a CR2032 ion battery with a battery life of up to 12 months Built in memory gives you the freedom to train without a phone, capturing data and syncing it to your phone later; Strap Length: Adjustable from 23" to 48" (stretched);Water Rating: IPX7 (waterproof up to 5 ft) Personalized Heart Rate Training - Workout efficiently - view real-time heart rate, training zones and calories burned on your smartphone or tablet with compatible training apps. Official HR Monitor of Team Sky, defending champions of the Tour De France. Bluetooth 4.0 and ANT+ compatibility allows TICKR to connect to smartphones and tablets, as well as GPS watches by Garmin, Polar, and more. TICKR works with iPhone 4S and later, and with select Android devices using Android 4.3. Works with Wahoo RunFit + 50 Smartphone Apps including Nike+ Running, MapMyFitness, Runkeeper, Strava, Apple Health, and more.