The Rolair 31104840CH Connecting Rod W/Upper Bushing helps transfer piston movement to the crankshaft for smooth compressor operation. This connecting rod links the piston assembly to the crankshaft, converting reciprocating piston movement into rotational motion. The upper bushing supports the connection between components and helps maintain proper movement during operation. Replacin... https://www.wholetoolbox.com/rolair-31104840ch-connecting-rod-w-upper-bushing/31104840CH.html