This is a stainless steel MFL tailpiece. This product makes it easy to switch beer and air lines from commercial Sanke kegs to Cornelius keg fittings. One end has an MFL fitting, while the other end will mount against a Sankey coupler as well as a shank.
You will need a FFL Fitting to attach beer or airline. 1/4" is used to attach 3/16" beer line or 1/4" air line hose. 5/16" is used to attach 5/16" air line hose. Choose one from the drop down menu below. If you choose a FFL fitting, you will also need an MFL washer.