900 Yard Range. 16 Levels of Intensity adjusted from the Transmitter. Digital Technology to Maximize Power. Maxx-Range? Internal Collar Antenna System. Lightweight, Compact Collars and Transmitters. Fits extra-small to large dogs. Built in Magnetic ON/OFF system. Completely Waterproof Collars. Weatherproof Transmitters. Rechargeable Ni-MH Battery System in the collar. Positive vibration available.