PRECISE DATA. TOTAL COMFORT. Compatible with any Bluetooth heart rate-enabled device, the COROS Heart Rate Monitor delivers over 38 hours of continuous accurate heart rate monitoring to track your workouts in distraction-free comfort. Comfortable and simpler to wear than a chest strap. Easy to adjust the fit and remove the sensor for quick cleaning. Our latest multi-channel optical sensor for precise measurement. Up to 3 simultaneous connections with Bluetooth-enabled devices. Wear detection allows for automatic device pairing for new workouts. 38 hours of full operation or 80 days in standby mode on a single charge. Rechargeable with a magnetic USB charging cable.  SLEEK & SNUG Simpler to wear than a chest strap, our soft fabric band lays flat around your arm and locks in place with its textured surface. The low-profile design prevents snagging on clothes or gym equipment, allowing you to forget you're even wearing it. FLEXIBLE FIT Set the perfect placement and tension on the durable elasticated band by simply sliding the buckle until it feels snug. The secure velcro enclosure enables you to quickly remove the sensor to easily wash the band. ADVANCED SENSOR Our latest Generation multi-channel optical sensor provides high signal quality. Housed in a tough yet sleek body and protected under a scratch-resistant cover, our advanced sensor will deliver reliable and accurate heart rate data for years. SUPERIOR BAND Optical heart rate sensors work best when they're held securely against the skin. Our band is designed to cradle the sensor flush against your arm to prevent external light from getting in to keep the signal quality strong, no matter your activity. LASTING POWER With 38 hours of full operation or 80 days of standby on a single charge, the COROS Heart Rate Monitor is built to endure. View the battery level on your COROS watch or app and use the magnetic cable to quickly recharge. WEAR DETECTION With built-in wear detection, the COROS Heart Rate monitor automatically powers on and off based on when it is worn. Allowing you to automatically connect to your paired devices every time you start a workout. MULTIPLE CONNECTIONS Designed to work seamlessly with your favorite COROS watches and app, it can also simultaneously pair with up to three devices, including non-COROS watches and other Bluetooth-compatible indoor trainers, bike computers, and more. Size and Weight Dimensions 42.5 x 28.4 x 9.1mm Weight - Sensor Only 9.7g Weight - Sensor + Band 19g Materials Band Material Polyester fiber, nylon, spandex Sensors Optical Heart Rate Hardware 5 LED lights with 4 photodetectors Fit Arm Size 7.09-12.6 inches (18-32cm) Wearing Position Bicep Connectivity Wireless Connection Bluetooth Supported Devices Bluetooth-compatible devices that receive heart rate data Supports simultaneous connection of 3 devices Data Sync Real-time heart rate data Durability Water Resistance 3 ATM Working Temperature -4°F to 122°F (-20°C to 50°C) Storage Temperature -4°F to 140°F (-20°C to 60°C) Charging Temperature 32°F to 113°F (0°C to 45°C) Battery Activity Mode 38 hours Standby Mode 80 days Battery Capacity 55 mAh Charging Time Less than 2 hours Charging Cable USB Type-A Connects to the sensor using a magnetic interface