Du-Bro Swivel Ball Link 2-56/4-40 with Hardware (2)This high quality ball link offers smooth, secure operation with less slop. You'd want to use this on any control surface where accuracy is required (like the throttle linkage).Includes:2x swivel ball link (Black plastic, self-threading for 4-40 rod, 1" in overall length) with a burnished brass ball pre-installed with a #2 hole in it2x 2-56 x 1/2" socket cap screw2x brass spacer2x 2-56 steel nutRequires:4-40 threaded pushrod5/64" allen wrench for tightening screw