This is a jalousie operator in an aluminum finish and a diecast construction with an offset crank handle. It is a left-handed design with a 4 in. link arm(center to center), and it comes with a matching aluminum finish crank handle that securely fits the 5/16 in. spindle. There are two mounting holes, 4-3/4 in. or 3-7/8 in. on the center for a more versatile fit.