The E-10 heart rate monitor make listening to your heart easy and affordable, allowing you to focus on your workouts without worrying about complicated multi-functions. The E-10 is designed to interface with heart rate interactive exercise equipment in health clubs, and their batteries are replaceable for the transmitter unit. Common Features Include: Large Dual Display, Easy to Start, Water Resistant, Comfortable Ultra-Slim Ergonomic Chest Belt Transmitter w/ user Changeable Batteries, Interfaces with Heart Rate Interactive Exercise Equipment at Home and in the Gym, Bike Mount Included. Heart Rate Functions: Current Heart Rate, ECG Accurate. Watch Functions: Time of Day