⭐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.

Versatality: Polar OH1 allows you full freedom of movement regardless of your sport. Wear Polar HR monitor either on your arm when rowing, cycling, running or training indoors or against your temple when swimming
Comfort: The soft textile armband keeps Polar OH1 snug around your arm. The swimming goggle strap clip, included in the Polar OH1 + package, keeps Polar HR sensor steadily in place when you swim
Connectivity: Pair HRM with the free Polar Beat fitness app, Strava or Nike, your sports or smart watch (Polar, Garmin, Apple, Suunto and others), bike computer or gym equipment (Peloton) via Bluetooth or ANT+ simultaneously