The Staywell 32 Magnetic/Manual locking cat flap is designed to be mounted inside most doors. The pet door controls access by a magnetic locking mechanism. The magnetic collar tag is approx. the size of a pea and worn on your pets existing collar. It controls access of other cats or feral cats by only allowing those pets with the collar tag to come into the home. It does not control pets from the inside going outside the house. The 4-way locking feature allows you to control the access of your cat by manually setting the locking mechanism in 4 different modes. The flap is rigid Zylar (Stronger than plastic) with a magnetic strip along the bottom to hold flap in closed position. The Staywell 32 has a 3-year manufacturer warranty.