Phillips #40 Expansion Joint is designed to control stresses in walls, ceilings, abutments, columns and partitions. The #40 Expansion Joint accomplishes this by the bends in the joint area, allowing the material to expand and contract from 1/4″ to 5/8″ openings, preventing cracking and other issues as a result of settling or shifting. This two-piece versatile product works great with a variety of applications. Phillips offers this product in a variety of sizes – 1/2″, 3/4″ and 7/8″ ground heights for your convenience along with your choice of materials – galvanized steel or zinc.