HBetterTech Helpful Remote Training Shock Static Vibration Anti Bark Collar for Medium Big Size Dogs Remote working distance: 250 m under ideal condition. It is safe for the pet.it can use 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 Power-saving mode of receiver prolongs the life of the battery.The soft remote controller antenna is anti-broken.Will work with dogs from 15 to 100 pounds dogs