Our cat is not the smartest cat in the world; he likes to push our glass shower door open to go in and then he gets stuck. He especially likes to do this in the middle of the night and meow until we wake up to let him out. To help him (us) out, I designed this door stop so you can't push the door in but you can pull it out. Mine is designed to fit right up to where the tile ledge but it also holds against the glass so should work with similar setups out there. You can modify the file as needed to suit your shower. The circles help reduce the filament needed but also help to lift up to remove the stop. I figured it might help others keep their pets/kids out of the shower.