1. Push according to the mark direction to open battery cover (Picture 1), put rechargeable batteries (UM-3, 1.5V * 2) inside. 2. Users may select the ways to wear their belt-pack transmitter, by changing the positions of clip on back of the transmitter. (Picture 2) 3. Please take the batteries out of the transmitter when stop usage, fo maintain the life of the machine. 4. BATTERY LOW LED: The red led will light up still when the battery is in low power.