The Classic Flap comes in many different sizes as highlighted below.
Style Dimensions (cm) Dimensions (in) Chain (cm) Chain (in)
Mini/Mini Square 16.5 x 12.7 x 6.4 6.5" x 5" x 2.5" 52 20.5"
New Mini 20.3 x 13.3 x 6.4 8 x 5.25 x 2.5" 56 22"
Mini Rectangular 20.3 x 13.3 x 6.4 8 x 5.25 x 2.5" 56 22"
Small 23.5 x 14 x 6.4 9.25" x 5.5" x 2.5" 22.9 - 43.2 9" - 17"
Medium 25.5 x 15.5 x 6.5 10" x 6.1" x 2.6" 22.9 - 43.2 9" - 17"
Large/Jumbo 30 x 19.5 x 10 11.8" x 7.7" x 3.9" 33 - 61 13" - 24"
Extra Large/Maxi 33 x 23 x 10 13" x 9.1" x 3.9" 26.7 - 48.3 10.5"- 19"