The Plastic Horseshoe Shims are made to simplify leveling problems wherever they occur, and have been approved by architects for use in the installation of windows, doors, curtainwalls, storefronts, and insulating glass units. They are adaptable for use in the appliance, automotive, aviation, and mobile home industries as well. They help cut labor and material costs wherever used. These Horseshoe Shims are made of high-impact styrene plastic, properly designed and balanced for vertical or horizontal use. They are available in three thicknesses 1/16", 1/8", and 1/4" (1.6, 3.2, and 6.4 mm), and three lengths 2", 3", and 3-1/2" (51, 76, and 89 mm). The 3-1/2" (89 mm) length is extremely popular for installing storefront aluminum since most major storefront fabricators use 4" (102 mm) tubing. You will find these valuable aids in your building requirements.