4 Pc Blue Aluminum Valve Stems With Caps For Tire/Wheel/Rim/Car/Truck/Suv for Ford F-150 This is a set of 4 stems with caps, as pictured. Stems are .5" (14mm) at the base. Made from weapons grade aluminum (.7"). Sickspeed is proudly displayed on each cap. Anodized for a brilliant long lasting shine.