[. . . ] Push one tab on the elastic strap through the slot in the heart rate monitor. sensors Configure Your GPS Device 1. [. . . ] Wrap the strap around your chest and attach the strap to the other side of the heart rate monitor. Tighten or loosen the strap as necessary so that it fits snugly against your body. April 2006 190-00651-00 Rev. B Printed in Taiwan Specifications Physical size: 13. 7"W x 1. 4"H x 0. 5"D Transmission range: approximately 3 m Battery: CR2032 (3 volts) Battery life: approximately 3 years (1 hour per day) Weight: 21 g Sensor Pairing What is pairing?Pairing is the process of matching sensors, like your heart rate monitor, with your compatible GPS device. This process occurs automatically when you turn on your GPS device and only takes a few seconds when the sensors are functioning correctly. Pairing tips: · Position your GPS device within 3 meters of the sensor while pairing. [. . . ] Use a coin to twist the cover counter-clockwise until it is loose enough to remove. [. . . ]