This is a faux nail head that supports 3m command strip for hanging a TRMNL device on the wall (see https://usetrmnl.com). The triangle nail head matches the triangular hole in the back of the TRMNL for easier alignment. The tolerances were made as small as possible to allow the TRMNL to sit as close to the wall as possible.

Since TRMNL is pretty light, and the nail head isn't too long, PLA should be strong enough to hold it up. This model is also printed at 100% for additional strength, but if you want more strength you can use PETG or even TPU since the peg is so short it shouldn't flex too much.