" Magnetic collar key helps keep out strays 4 locking options: in only, out only, opened, locked Suitable for cats up to 7 kg (15 lbs) Overall size: 224 mm x 224 mm (87/8" x 87/8") Cut out size: 169 mm x 169 mm (65/8" x 65/8") Glass cut out: 210 mm (81/4") diameter circle Maximum pet shoulder width: 162mm (63/8")"