Summary This is a door latch extender that will allow you to open a door but not let it open all the way. The reason for this could be for a really dumb dog that likes to eat poop out of a cat box. So, perhaps, you would like to keep this sed dog out of the laundry room where the kitty litter box resides. This allows the cat to get in and out but not the dog. ...or you may have other reasons for it. There are two versions: Split and No Split Since my printer was so small I had to make the model in two pieces. If you are like most people you can just download the "no split" STL and that should be all you need. I added two holes at the end so you could pick between two opening widths. Print Settings Printer: Micro M3D Rafts: No Supports: No Resolution: .25 Infill: 100% Notes: I used gray ABS on my Micro M3D printer... but I also have a heated bed on the M3D It is 150mm long Post-Printing if you use the split model... you can use Acetone to weld the ABS together. How I Designed This Used OnShape It is public in OnShape, just search for "Door Latch Extender"