The Rapid Access button provides quick corrections. This system can expand to a 2-dog or 3-dog system. The small, lightweight collar unit fits in the palm of your hand. The collar is waterproof, rechargeable, and fits small to large dogs. The transmitter FLOATS on water. Patented, revolutionary curved transmitter design and function with 3 grip positions: "Knuckle Grip" - On back of the hand to free up both hands and have a quick, no look button. "Palm Grip" - In palm of hand holding like a stopwatch. "Pistol Grip" - More traditional hold with thumb operating most buttons and trigger finger on top "Rapid Access" button. Features: Nick, Continuous, Vibration Assist, and Jump stimulations. MAXX-Range 360 internal collar antenna system. Extra mild gentle touch stimulation system. Transmitter "Lockout" feature prevents accidental stimulation. Lightweight, compact collar design. Built in Magnetic ON/OFF system. Rechargeable (NiMH batteries) and completely waterproof Collars. Waterproof FLOATING Transmitters uses 9V battery (not included). Fits small to large dogs. Adjustable R.A.P.T. strap on transmitter offers secure and comfortable fit Rapid Access button programmable to be Nick (default), Continuous, or Vibration Assist Expandable to 2-dog or 3-dog system with R.A.P.T. Add-On collars 1400 Yard Range 16 intensity levels of Nick and Continuous stimulations adjusted from the Transmitter