Training your dog is easy at home or at the park-up to 100 yards away. Ten quickly adjustable levels of stimulation, plus a tone-only option make this an ideal choice for hard-to-train dogs. Lightweight, waterproof receiver collars have quick release buckles and use 3-volt batteries. Hand-held transmitters are weather resistant and use standard 9-volt alkaline batteries. Fits up to 30' neck size.