Manufacturers Specification   Output :5V, 0.5A   Remote control: remote control distance 800m (no interference)   Receiver charging time :4 hours   Material: plastic   Product category: dog trainer   Channel: there are three signal channels on the remote control, which can control three receivers of the same type   3 training modes: shock/vibration/sound   Lost: 100-240V,50/60Hz Battery type: lithium ion battery (built-in)   Charging time of transmitter :4 hours   Specification: 880-3,880-1,880-2   Adjustable collar size: maximum adjustable length up to 67cm, suitable for all sizes of dogs   Transmitter battery voltage: 3.7V