EXTRA BIG GAME ANTLER INSERTS Elk, Moose, Stag, Caribou XL Antler Inserts | US Patented: No. 11,535,051 Do you have too many antlers lying around, and you don't know what to do with them? Well, GOOD NEWS! You could buy more XL ANTLER INSERTS to swap them out on our RACK HUB® products! These inserts are manufactured with high precision aluminum and then finished in a protective matte black coating. These inserts are PATENT PENDING and will work with all of our XL Products.