This is used to attach a Honeycomb Storage Wall (HSW) tile to a wall using M5 bolts. It's very similar to the M3 attachment object included in the HSW project, but with larger holes and a “cone" used to convert the countersunk holes into holes useful with flat M5 bolts.
The cone is only necessary if using standard (as opposed to countersunk) bolts.
With the cone, bolts should be roughly flush with the top of the insert.
The author remixed this model.