Keystone adds 0 3/4"H to the crosshead height for an overall height of 8"H Remodelers, builders, and homeowners looking to enhance their next project by adding more curb appeal to the exterior of a home should consider crossheads. Crossheads are large casings that are typically placed at the top of a window, doorway or large entryway. Made of lightweight, yet durable high-density polyurethane, crossheads are easy for anyone to install. Feel free to choose from an amazing selection of sizes and style that will suit your project needs.