The Microchip flap works with your cat's implanted microchip or unique I.D. disc (sold separately) to allow your furry friend to pass through while keeping all unwanted critters out. It can connect up to 30 cats and features an easy to use rotary 4-way lock that enables complete control over your cat's movements. It has a transparent flap made from tough polymer and comes with a 2 year warranty. Rest comfortably knowing you're giving your furry friend the safety and freedom she deserves while keeping unwanted critters out. Microchip flaps are non-refundable.