Namsan Cat Puppy Door for Screens Door Cat Window Door Small Inner Size: 8"H(25cm) x 10"W(20cm) opening. Only suitable for cats and small dogs (puppy/doggie). Installs easily,For screen doors and windows. Installs easily,For screen doors and windows, please Using cable tie to fixed it(As the picture showing) Fits all door and window screens, Suitable for all pets up to medium/large size dogs Durable, self-closing pet screen door,Not included the Screen Namsan's order just need usually 6--14 days arrived your home(Not as Amazon system shows:14--28 working days),FBA items can arrived within 1--5 days Available in S,L Durable self-closing pet screen door For cats, small dogs, medium sized dogs and medium/large dogs. Install easily