Adjustable size: the size is one meter in length, and the distance between the two holes is 45mm.
Compatible with heart rate sensor: Support 5MM center distance heart rate belt with universal Bluetooth transmitter.
Made of nylon and spandex material to fit your skin tightly. The soft fabric and electrodes make it sensitive to your heart’s electrical signals.

Make sure this fits by entering your model number.
1.1″ Full Color AMOLED Screen: Big, Bright, and Beautiful
Continuous SpO2 Monitoring: Constant Health Protection

【ATHLETE TESTED RELIABILITY】Our heart rate monitor armband has been tested by professional marathon runners, mountain enthusiasts and mountain cyclists. It shows that V9 built-in precision optical heart rate sensor technology provides highly accurate monitoring and measurement during your each exercise to help you optimise and get most out of your workout!
【BLUETOOTH & ANT+ DUAL MODES】V9 armband heart rate monitor support all device with Bluetooth and ANT+. Easy to connects with smartphones, tablets, sports watches and bike computers. Track and capture real-time heart rate, training zones and calories burned on your smartphone or tablet with compatible training apps.
【APPS COMPATIBLE】Works with most mainstream health and fitness apps like Polar Beat, Wahoo Fitness, DDP Yoga, Endomondo, Nike Run Club, Runtastic Pro, Zwift, Strava, Peloton, and more. Compatibility-iOS mobile devices: iPhone 5 and later, with iOS 11 or later. Android mobile devices with Bluetooth 5.0 capability and Android 5.0 or later.

⭐Comfortable Chest Strap or Strap-Free Wear Way: 1. The adjustable soft chest strap makes carrying more comfortable. 2. Strap-free, no constrain to the chest, wearing with the electrode patches will be more convenient and provides a stronger and more stable signal. The lightweight feature gives you a carefree wearing experience. Always accurate during exercise.
⭐ Accurate real-time heart rate with ECG: The heart rate monitor can not only track your heart rate continuously throughout the day, but also record your waveform for up to 30 minutes (click “Record” and stay on the dashboard interface). * Note that the EKG can only be monitored if you connect to the APP via Bluetooth. Please measure your ECG in the resting state. The maximum recording length is 30 minutes. If the recording time is less than 30 seconds, the recording is not saved.
⭐Heart Rate Vibration Alarm : The built-in vibration alarm helps maintain the best heart rate zone (of your choice) during the workout. It vibrates every 10 seconds if your heart rate reaches the ideal heart rate (target 1) and vibrates every 2 seconds if your heart rate reaches the dangerous heart rate (target 2). Helps you achieve the best training results and health training routines.