Noted: There are two size for optional: For 1 dog:（1 Transmitter + 1 Receiver Collar） For 2 dog: ( 1 Transmitter + 2 Receiver Collar ) For 3 dog :( 1 Transmitter + 3 Receiver Collar ) Why You Need a Training Collar? Your probably are tired of your dogs Excessive barking, running away suddenly, peeing in the middle of the street, biting shoes and other items in the house or other bad behaviors. Dog training collar is a training tool used to help correct Barking, Walking, Leash Training, Sitting, Aggression, and other Behavioral Obedience. Besides, it is easy to use and make your training process less painful and as stress free as possible. Features: 1. 865 yards (2600ft) super long remote control range 2. IP65 Waterproof collar Receiver 3. 4 working modes - Vibration, shock, Tone and LED Light 4. Adjustable Collar fits neck size from 18-65cm; Soft and Comfortable for your dog 5. Rechargeable Lithium Batteries for Receiver and Transmitter 6. One transmitter supports to remote up to 3 receivers 7. LCD display of dog training controller featuring a blue backlight for both day & night. 8. LED Light bulit in receiver helps to locate your dog at night 9. Conductive silicone sleeve on contact point is better to avoid skin damage during training 10. Comes with detailed User Manual and Dog Training Guide Package Contents（for 1 dog）: 1 * Remote Control 1 * Receiver 1 * Charging Cable 1 * Adjustable Nylon Collar 1 * Power adapter 1 * Manual Package Contents（for 2 dog）: 1 * Remote Control 2 * Receiver 1 * Charging Cable 2 * Adjustable Nylon Collar 1 * Power adapter 1 * Manual Package Contents（for 3 dog）: 1 * Remote Control 3 * Receiver 1 * Charging Cable 3 * Adjustable Nylon Collar 1 * Power adapter 1 * Manual Notice! 1. Please read the manual before using. 2. Proper fit of the collar is quite important. Long-time wearing may cause skin damage. 3.Light on the collar will flash every 3s while it's on or charging.