This is the window regulator and motor for the front left (LH) window on many different GM vehicles from 1999-2014. This is a used, factory OEM, genuine GM part, that is in working condition with normal wear and tear. This is guaranteed to work, although it squeaks. You could probably lubricate the tracks and the cables and get rid of the squeaking.

GM part # 20914717

Alternate GM Part #'s 20945138 ; 25885878