Staywell Deluxe Magnetic 4 Way Cat Flap 400 is a magnetic cat flap and limits entry to cats wearing magnets. Helps keep strays and other animals out of the house. Manufactured from tough, easy clean, heavy duty thermoplastic. Easy to fit with full instructions. See through, weather resistant, self closing magnetic flap. Includes Tunnel Extension. Depth can be extended by use of the Staywell 310 Tunnel Extensions. Contains 1 collar & 1 magnet. Additional collars/magnets can be purchased. Colour White Overall Size Cut Out Size Glass Cut Out Size Max Pet Shoulder Width 241mm x 252mm 168mm x 175mm 212mm diameter 150mm Suitable for fitting into doors, walls or glass to a maximum depth of 54mm (2"). Depth can be extended by using Staywell 310 Tunnel Extensions. If a flap is to be fitted into double glazed, toughened or tempered glass, then this can ONLY be done so at the time the glass panel is manufactured. IMPORTANT The cat flap will not operate if fitted to a door containing metal e.g. UPVC coated metal doors, metal skin doors or security doors. The cat flap must be isolated from the metal in a wood frame, as detailed in the instruction booklet.