If you're a do-it-yourself person looking to build a tap handle from scratch, or you need a replacement part, this is the finishing piece that you see at the bottom of most handles. You must also get the D1298B if you want to screw it into a wood tap handle.
These ferrules fit onto the bottom of my tap handles using a basic hangar bolt that can be found at any hardware store. Drill a set hole into the wood of the handle, screw in the pointed end of the bolt until maybe 1/2-inch of the bolt's flat end is left exposed, and then attach the wide end of the ferrule onto the bolt. The other end of the ferrule fits on a standard beer tap faucet. Looks all shiny and new, and it works. Can't complain about that.