Philips 140947 High Intensity Discharge High Pressure Sodium 70-Watt ED23-1/2 Mogul Base Light Bulb Philips 70-Watt HID High Pressure Sodium light bulbs offer premium light quality and energy efficiency Ideal for use in parking lots, dusk-to-dawn fixtures, roadway lighting, and industrial and commercial applications Mogul base  this bulb is for a very specific application, please see bulb dimensions and install only in a fixture with an ANSI S62 ballast and appropriate size housing based on bulb dimensions Mogul Base ED23.5 Shape C70S62 for use with ANSI S62 ballast