I made this on Tinkercad. The space that it holds is 1 inch (25.4 Millimeters). The space is between the last bar on the cage door, and the next bar on the wall that is closest to an inch apart from the last bar on the cage door. If you have any questions, feel free to ask in the comments, like, download, comment, rate, and share your make! Do not sell without permission and put my name on it plz! Thanks for checking my lock out. Tested and works, getting it on and off has been tested, even if the dog unlocks the main lock, this will keep the door closed, even with pressure against it. Make sure your dogs has mental stimulation toys in the crate. The crate is not a punishment. Do not lock a dog in a room with a running 3D printer on, as it is harmful to theirs (and our!) health.