Kit includes Humane Contain model X-10 rechargeable multi-function electronic dog fence and Power Pet PX-2 large automatic pet door. One collar controls both systems. The X-10 electronic dog fence provides the most advanced technology for highly humane and reliable operation. A proprietary technology automatically adjusts stimulus intensity based on the dog"s distance from the boundary. This keeps a dog reliably contained without unnecessary overstimulation. The waterproof, lightweight collar has a rechargeable battery. The system comes with a waterproof, outdoor-mountable transmitter with coded digital signal, illuminated panel, audible and visual wire break alarms, power boost switch and variable field width control. The transmitter also accepts an optional, rechargeable back-up battery (model B-12V-0.8) that keeps the system operating during a power outage and automatically recharges when power is restored. Power Pet doors are motor-driven and collar-activated. Other electronic pet doors merely unlock a hinged panel, requiring your pet to push it open. Power Pet doors open under their own power. They feature a translucent door panel made of a super-strength, bulletproof resin. When your pet approaches, the air-tight panel quickly and quietly moves upward, disappearing into the housing. Because the panel moves vertically and does not swing out, it can be mounted in sealed grooves for air-tight closure. This makes it impossible for an intruder to kick it out. An automatic dead-bolt locking feature adds a higher level of security to your home, resulting in the most secure pet door against intruders and stray animals. Completely wind and weatherproof with an air-tight sealing system. The digitally coded signal emitted from your pet"s ultrasonic transmitter collar allows the Power Pet to work almost like magic, opening only when your pet is on a direct approach. Panel size: 12-1/4 X 16-inch for pets up to 100-pound.