Super B TB-1900 bottom bracket assembly tool

Bottom bracket tool retaining system. Used with most Super B bottom bracket wrenches, 1/2″ Dr. bottom bracket tool and some 3/8″ Dr. bottom bracket tools, ensuring that they are fully engaged with a threaded external cup bottom bracket to prevent slippage. Fits threaded cup & thread-together bottom brackets with external cups; can’t fit cartridge & cup-and-cone bottom brackets.