moofit HW401 Heart Rate Monitor Armband, IP67 Waterproof, Support Bluetooth/ANT+, Rechargeable Optical Heart Rate Sensor Bracelet Works with Wahoo, Strava (Dark black)

Precise Arm Strap Heart Rate Sensor – Optical sensor technology for a high-precision heart rate monitor that has been tested millions of times and has an accuracy of up to ±1 bpm. It records real-time heart rate data during training, analyzes your fitness data to maximize your training results.
Bluetooth & ANT+ Dual Mode – The heart rate monitor becomes your fitness tracker, connects to various fitness equipment and apps. Whether outdoor fitness training or indoor cycling or group training, heart rate and calorie consumption are precisely determined.
LED Light Reminding – HW401 heart rate sensor has a flashing LED light that confirms your heart rate and connection. Turn-on: LED light will flash blue quickly until the heart rate was found, then the blue light will flash slowly. Turn-off: red LED flash, enter the shutdown state.