The Cat Mate Large Cat Flap is specially designed for the largest cats or even for small dogs such as Yorkshire Terriers Pekinese Dachshund Miniature Poodles and Spaniels up to a shoulder height of 36cm.The easy to use 4-way locking system allows you to set the flap to Unlocked In Only Out Only or Locked.Self lining to 50mm thick the Large Cat Flap is ideal for all doors and thin panels. The flap's silent action will not frighten pets or disturb their owners. The transparent magentically closing flap is preferred by most cats and the flap is draft and weatherproof.Measures 23.5cm wide x 25.2cm high cut out size 21cm wide x 22.7cm high.