Includes bulb and socket assembly with red and green bulb coversBronze bourdon tube 270 degree sweep movements and durable nylon gearing make rugged and long lasting gauges a proven high performance favorite for over 25 yearsRequire no electrical power for operation and indicates oil/water/voltIdeal choice for vehicles with no or low powered electrical systemsIncludes 1/4 inch, 3/8 inch, 1/2 inch NPT adapter/fitting