This series features single and multivolt models with stem mount. All models are equipped with a light level slide adjustment and provide a 1/2"-14 threaded stem. A washer gasket and locking nut are packaged with each photo control. Models with "M" suffix have heavy duty die cast housings. Tungsten Wattage is 3100 - 4150. Product features 1700 - 2300 ballast.