Wodondog Dog Training Collar Rechargeable and IPX7 Waterproof 870yards Remote Dog Shock Collar with Beep Vibration and Shock Electric Collar Dogs Blind Operation: Has user friendly interface to operate it. Three simple button to switch the working mode freely,especially a good design for a blind man. Multi-dog System: This system can be use to control 3 dogs with one transmitter just need to purchase extra receiver collars and add them to your system. 4 Training Modes: With Beep, Vibration, Shock and LED Light 4 training mode. The dog collar stimulation can adjust with 0-99 levels of customization. 870yds Remote Range: Works within a distance of 870yds.The range will vary according to terrain, weather, vegetation, as well as transmission from other radio devices. Easy and Quickly Synchronize: Quickly receive training collar signal within 10 seconds. Ingenious design over 3000 different identity codes that prevents conflict with other similar devices.