Extension tunnel for use with PetSafe Classic Cat Flap when the door or wall is too deep for the cat flap. Single or multiple extensions can be used as necessary to form a comfortable sleeve between inside and outside flaps.The Classic Cat Flap can fit doors, windows and walls of up to 57mm depth and wider, if optional tunnels are used. Each Classic tunnel can add 17mm depth to the overall sleeve. So, using one tunnel will accommodate a door width of 74mm, 2 tunnels will accommodate up to 91mm etc.
