Horseshoe Shims. Box of 1000. 14HS. Thickness: 1/4". Size: 1-1/2". Color: Black. Typically withstanding ten tons of compressed force, lightweight plastic U-shaped shims are designed to fit around bolts and anchors. Often used for aligning windows and curtain walls. The rounded shape allows greater flexibility in aligning the plastic U shims with no protruding corners. Offered in eight sizes as well as four color-coded thicknesses. Ideal for the Countertop, Precast, Tilt-Up, and Glass industries.