Udoarts HRM with Pedometer- Heart Rate Monitor & Chest Strap 2&Pack of 5 Batteries &Screwdriver REAL-TIME HEART RATE DATA FOR ACTIVITIES - Displays continuous heart rate ,exercise time , steps, distance, calories burned - Reminds you doing exercise within the preset training zone to keep your fitness smart and safe TRACK EXERCISES - Provides 8 operation modes to help people achieve exercise goals based on heart rate or other sports data FASHIONABLE AND HUMANIZED DESIGN - Wears the watch on your wrist or fixes it on bicycle - Allows you to get the best pose and condition for running, cycling, climbing, etc.- Replaces batteries easily MORE ACCURATE WAY ON THE MARKET- Monitors heart rate with the chest strap to get the most accurate value- Includes the heart rate chest strap 2 made of soft fabric material that perfectly and comfortably adapts to your body shape ONE SIZE FITS MOST- The chest strap can be stretched from 60cm to 145cm When you use the HRM, you should avoid interference sources such as mobile phones, computer, Wifi, etc. It is very important that you should wear the chest strap in a right way before monitoring heart rate. Get the conductive mat on inner side of the chest strap wet with several drops of water to ensure good contact Wear the chest strap alone under your chest tightly and ensure the logo of the brand is up Wear the watch on your wrist or fix it on bicycle with a distance65cm from chest strap emitter Ensure the battery of chest strap is full. You could try to replace a new one for the chest strap