Bark Stopper Pet Supplies Collar Remote Control Collar Dog Training Device, 880-1 Black, 880-1 Green, 880-2, 880-31. Material: ABS, nylon webbing 2. Function: collar, dog training device, barking control device 3. Power source: USB power supply built in battery power supply 4. Built in battery: 300mAh lithium battery 5. The product has a built in lithium battery, which can last for a long time 6. The neck strap size is 25 75 cm, suitable for most dogs 7. With waterproof function, please rest assured to use 8. Please turn off the power if not used for a long time