The High Tech Pet Power Pet Electronic Pet Doors are motor driven and activated by a tiny ultrasonic collar. Unlike other electronic pet doors that merely unlock a hinged panel, requiring your pet to push it open, patented Power Pet doors open completely under their own power. These doggie doors feature a translucent door panel made of super-strong, bulletproof resin. When your pet approaches, the airtight panel quickly and quietly powers upward, disappearing into the stylish housing. Mounted in hermetically sealed grooves for airtight closure, this mounting arrangement makes it impossible for an intruder to kick it out. An automatic dead-bolt locking feature adds a high level of security to your home. The result is the most secure pet door against intruders and stray animals. Your pets are empowered to come and go as they please. Their animal friends are politely asked to stay out. The digitally coded signal emitted from your pet's ultrasonic transmitter collar allows the Power Pet to open only when your pet is on a direct approach. 4-way access control lets you select from In Only, Out Only, Full Access or Closed and Locked. Dual range controls let you set independent inside and outside activation distances. Plastic & metal Limited warranty Operates on AC adapter (included) Optional backup battery (model B12V-1.3) available for these doggie doors Electronic pet door is also operated by Humane Contain RX-10 multi-function collar for X-10 dog fence system Medium Specifications: Panel Size is 8-1/4 by 10 in. for pets up to 30 lb.; 2 in. x 12 in. x 28-5/8 in. (assembled) Large Specifications: Panel size is 12-1/4 by 16 in. for pets up to 100 lb.; 2 in. x 16 in. x 40-5/8 in. (assembled)