Scosche Rhythm24 Waterproof Armband Heart Rate Monitor – Bluetooth Compatible, 24-Hour Battery – Blue

HYPER-ACCURATE - Patented optical sensor technology for highly accurate monitoring and measurement. Green + Yellow Optical Sensors Provide superior measurement with all skin tones. Better than monitors and watches that employ only green sensors. On Board Recording allows you to leave your mobile device behind, record workouts and upload data to your device later.
WORKS WITH VIRTUALLY ANY DEVICE - Great for use with smartphones, tablets, smart and sport watches, exercise equipment and many other devices that support Bluetooth Smart or ANT+ heart rate data. Works with over 200 of the most popular fitness apps and group training environments.
27 HOUR BATTERY LIFE - Extended use rechargeable battery allows you to workout for up to 24 continuous hours.
CUSTOMIZABLE - Change HR zones and modes in the RhythmSync app. Modes include Heart Rate Only, Running (Cadence + Distance), Cycling (Cadence), Swimming, Heart Rate Variability (HRV). Multi-Modes include Duathlon (Cycling and Running), Triathlon (Swimming, Cycling, Running).
INTERCONNECTED ARMBAND DESIGN - The Rhythm24 has an updated quick-lock interconnected armband design to keep the Rhythm24 securely attached to your arm during swimming, cycling, running, and other intense workouts.