This Zinc plated Caster Camber shim is for front upper control arm suspensions that feature a cross shaft and a 9/16" opening (H/D trucks). Fits control arm shaft mounting bolts up to 9/16" diameter, including 1/2 Ton - 1 Ton Chevrolet/GMC trucks, HD service. 1/16" (1.5875mm) Thickness. 50 per box.