Problem Solvers Derailleur Hanger Plug

The Problem Solvers Derailleur Hanger Plug is made of stainless steel and screws into the derailleur hanger on your frame to seal it and protect the threads from dirt and corrosion when you're turning a bicycle into a singlespeed, fixie or hub-gear bike. The plug is tightened from the inside so from the outside all you see is a nice custom finishing touch.