HO/OO Bearing Box set of 4

This product was a request from one of my patrons.  This product is used to fill in the holes on the axle boxes of my products to make them look more realistic.  This product should be compatible with any of my products which use a stationary axle system (i.e. any product that doesn't feature bogies).  All you have to do is insert the peg part of the product into the hole of the axle box and glue the part on.