Du-Bro 1/16" Threaded Ball Link Part No: 190. This 4 piece set fits perfectly in servo arm hole, bellcranks, nylon horns, and throttle arms. Set includes \(1\) ball threaded for 0-80 \(1/16" diameter thread\), \(1\) self threading nylon socket, \(1\) threaded coupler 3/4" long with 3/8" 2-56 thread for up to .072" rod.