The Remote Trainer has 3 components; 2 collar device (receiver) and a hand- held remote control unit. It uses vibration or micro static shock to modify your dog"s behavior and a whistle tone reward for positive reinforcement. You can use this product to deter them from such behaviors as digging, getting into the trash, chasing cars, stealing food from the counter, running away from you, etc. Matching Receiver and Transmitter : 1. Turn on the transmitter by the switch on right side of it 2. Install the batteries for the receiver. The LED inside the receiver starts to keep flashing. Press vibration or shock button immediately after batteries are put into the receiver firmly. Then the LED will stop flashing and only light which indicates that the transmitter and the receiver have matched each other successfully. 3. If LED stops flashing on its own without press any button in the transmitter, take out the batteries. Wait for at least 10 Seconds and try step 2 again. 4. Put the cover on the receiver firmly 5. Attach the receiver to the collar. Features: 1. Remote training collar with LCD display. 2. Patented design. 3. For mild-mannered to stubborn disposition dogs. 4. Easy to use and ergonomic transmitter. 5. Rheostat dial allows for gradual adjustment in stimulation intensity. 6. With no jumps between 0 and 100 levels. 7. 300 meter range. 8. Static and vibration mode. 9. No external antenna on collar. 10. Easily visible LCD screen displays level of stimulation. 11. Over 3,000 different identity codes to prevent conflicts with other e-collars. 12. Three bar battery life indicator on transmitter. Specification-Collar: Length: 43mm Height: 68mm Width: 38mm Collar length adjustable from 35cm to 58cm. Weight: 56g (module + battery) Power: 4 x 1.5V AAA battery (included)