Remote Control Electronic Shock Dog Training Collar Pet Training Collars Vibration with 6-level Shock for Small/Medium/Big Stubborn Dog Remote working distance: 250 m under ideal condition. The soft remote controller antenna is anti-broken. Adjustable collar length (from 8"to 20") fits different size of dogs. It is safe for the pet. The conductive rubber electrode is soft and the static impulse can penetrate the hair of the pet. It is comfortable for the pet to wear. The strongest static impulse can quickly and effectively curb the improper deeds of the pet. The vibration call can help the master communicate with the pet gently. It will let your pet associate the vibration with static impulse. At the end, vibration will achieve the same effect as the static impulse.