Washer & Screw Set are washers made of galvanized steel that are used to attach Kerdi-Board panels to wood-frames or metal structures using the appropriate screws. They have legs that penetrate the surface of Kerdi-Board and temporarily hold them in place to facilitate installation. Schluter-Kerdi-Board-ZS screws are mounting screws used to attach Kerdi-Board panels to wood-frames or metal structures using appropriate washers.