Straightforward online ordering with usual confirmation email. Fitting the cat door was straightforward enough using the template provided as a guide for my jigsaw. The magnetic tags hang on a ring that slips over the cat collar so that it swings freely underneath. Both my cats took time getting used to this but the mechanism opened the cat door effectively. Having had a rival version some years ago their magnetic attachment fitted snugly onto the cat collar without the movement and I think this was better. Not sure what happens if another cat is fitted with the same device?