Petsafe Electronic Dog Door

This Electronic Dog Door opens and closed automatically as your dog wishes. Using radio-frequency technology, the SmartDoor™ reads the unique signal of a SmartKey™ worn on your pet's collar and triggers the battery power-driven flap to unlock. When the door no longer senses your pet's SmartKey™, the flap automatically locks back into place. The unit can detect up to five programmed SmartKeys™ and also operates in two other modes: fully locked mode and unlocked mode. Locked mode does not allow entry or exit for any pet and unlocked mode allows entry and exit for all pets. Uses 4 D-cell batteries, not included. White only. Small for dogs up to 15 lbs - $149.95 Outer frame dimensions: 9in w x 15-5/8in h . Flap opening dimensions: 5-1/2in w at center x 7-7/8in h Cut-out size: 8-3/8in w x 14-3/4in h Large for dogs up to 100 lbs Fits door thickness 1 1/2" to 2" Outer frame dimensions: 16-1/8"w x 23-5/8"h Flap opening dimensions: 11"w at center x 16"h Cut-out size: 15-5/8"w x 23-1/4"h One Smart Key comes with each door. Additional keys are available.