GENUINE POWER PET AUTOMATIC PET DOOR from HIGH TECH PET Brand. This is the Original, Reliable Automatic Dog and Cat Door. Engineered, Assembled and Serviced in USA. DEAD BOLT SECURITY: Automatic Dead Bolt Lock protects against would-be doggy door intruders. Keeps out raccoons and other stray animals. Attractive. Translucent Panel is Bulletproof, Shatter-proof and Cannot be Forced Open or Lifted From the Outside. SAFE GRAVITY CLOSURE with AUTOMATIC ANTI-PINCH SYSTEM: Closing the pet access panel is intrinsically safe because the panel is lightweight and closed by gravity, not the motor. In addition our patented anti-pinch system automatically reverses the panel and drives it upward should it encounter an obstical during closure. 100% AIR TIGHT, WIND AND WEATHER RESISTANT: Hermetically Sealed Panel is 100% Air Tight and Draft Free, Even in Hurricane Force Winds. Keeps your home energy efficient. NO DRAFTY FLAPS! SMOOTH, FAST, QUIET OPERATION: Developed by expert electro mechanical engineers to open in time for the fastest dogs with whisper quiet operation. 4 WAY ACCESS CONTROL: Exclusive Power Pet Feature. Select from ENTER ONLY, EXIT ONLY, FULL ACCESS or CLOSED & LOCKED. DUAL SENSOR SYSTEM: Control Individual Inside and Outside Activation Ranges from 0 to 30 feet. DIRECTIONAL SENSING: Unique Directional Sensing System Opens the Door Only When Your Pet is on a Direct Approach, Not When Just Wandering by or Sleeping Next to the Door. DIRECTIONAL SENSING: High Tech Pet's patented sensing system detects the direction your pet is traveling and opens only when your pet is on a direct approach to the door, not just wandering by, standing or sleeping next to the door. This greatly reduces false openings. MEDIUM PANEL SIZE: 8-1/4" by 10" high. For Pets up to 30 lbs. POWER: Powered by AC Adapter or Optional Rechargeable Battery (ASIN B003NTIQBA). A BRAND YOU CAN TRUST: Since 1986 High Tech Pet has been the leader in creating and manufacturing the highest quality, most innovative automatic pet doors. We support our USA assembled products with live, friendly, knowledgeable, HUMAN customer service experts to assist you when you need us. Note: Please look at specs image to make sure the door you order is the correct size for your needs. This PX-1 (Medium) door is appropriate for most dogs up to 30 lbs. If your dog is 30 pounds or overweight, please measure to make sure the dog panel will be large enough. If you are not sure, it is best to order the large size door (PX-2).