Replace an unused 4" gauge with two new 1-1/8" style gauges. Place the face plate in front of the dashboard then inserting the socket/meter in the hole with the washer behind. The assembly is held in place by the socket/meter nut for a clean finished look. UV resistant injection molded nylon. A 3-3/4" B 1-3/16" C 3/16" D 3-3/8" E 1-1/16" F 1/8"