4 IN 1 training dog collar Remote Pet Training Vibra & Electric Shock and LED light The strong static impluse can penetrate the hair of the pet and fabric within 6mm thick.It is unnesscessary to let the discharging point touch the skin of the pet.Therefore it is safe for the pet. The warning vibration will let the pet associate the vibration with static impluse. In the end, the vibration will achieve the same effect as the static impluse. Both the static impluse and warning functions are set with automatic stop. This is for not reprimanding the pet continuously. With the vibration induction power switch in the collar receiver,it will turn on and off automaticlly to save power. Water resistant collar , but you can't immerse it into water and use it in the storm.