Accuro HRM302 Heart Rate Monitor w/Bluetooth and ANT+ Weight (transmitter, textile strap and battery): 0.1 pound (47 g) Transmit heart rate data to smart devices running Accuro Health App via Bluetooth for use outside of an ANT+ environment Heart rate measurement error: &lt; 1 BPM Fits chest size 19.6 to 37 Battery: One CR2032 (included)