A Sam’s Club Exclusive - Smarty Pets Medium Automatic Pet Door Value Kit includes an automatic pet door complete with U4 collar and rechargeable back-up battery. Engineered for performance, design, value and extreme reliability, the Smarty Pets Automatic Pet Door is an electronic pet door that opens completely under its own power. It features a translucent door panel made of a new super-strength, bullet-proof resin. When your pet approaches, the air-tight panel powers upward, into the stylish housing. Because the panel moves up and down and does not swing out, it can be mounted for air-tight closure. This mounting arrangement makes it impossible for an intruder to kick it out. The result is a zero-draft, wind and weatherproof pet door that is easy to use for your pet and very secure against intruders and stray animals. For cats and dogs up to 30-pounds Operates on AC adapter (included), or rechargeable backup battery (included), which snaps into the battery compartment to keep your Smarty Pets door functioning in the case of a power outage Optional battery charger kit (sold separately) lets you operate your Smarty Pets automatic pet door without an AC wall connection