This is an adapter to put the nylon sheath of a Leatherman Signal in line with your belt. This way it doesn't dig into your sides as much. The regular file takes a good amount of “aggressive negotiations” to get the sheath into the adapter. I used allen wrenches to stop the belt loop from catching on the latch. You can probably just print the “less-indent” version. I don't think it'll slip but I haven't field-tested it.
Also check out https://www.printables.com/model/98898-leatherman-90o - I printed his design first but it fit neither my belt nor my nylon sheath.
The author remixed this model.