End piece bracket that holds the drawer slide rail at the far end of the cabinet or desk. Here's a picture of my broken one that this printable thing replaces:

Prints without supports, and I've used them in PLA and PLA+.  (Just whatever I happen to have loaded up in my printer at the time the drawer decides to break.)
 
I usually fasten these in using 1" drywall screws or small wood screws that I have lying around.

Pictures of the slide rail used and rough scale measurements provided for your reference to judge whether it's the same rail system you are using.