This adapter is used to back flush your draft system, cleaning out your shanks, tubing, keg connectors, etc. all the way back.
To use this adapter, attach the barbed end to a tube connected to your vessel of cleaning solution.
The other side screws directly into your coupling nut on your shank. You must remove your faucet to use this.
Pressurize your vessel of cleaning solution to push it through the tube and into your shank, ultimately running through your entire system.