GE 42729 250-Watt Multi-Vapor Quartz Metal Halide Mogul. Base Temperature [Max]: 210 -DegreeC, Bulb Diameter (DIA) [Nom]: 3.500 cm, Bulb Finish: Clear, Bulb Material: Hard glass, Bulb Temperature [Max]: 400 -DegreeC, Burn Position: Universal burning position, Color Rendering Index (CRI): 65, Color Temperature: 4,200 K, Effective Arc Length: 1.400000 cm, Hot Restart Time to 90 percent [Min]: 10.000 min, Hot Restart Time to 90 percent [Max]: 15.000 min, Initial Lumens [Avg]: 19,100.00, Initial Lumens [Typ]: 20,800.00, Lamp Enclosure Type (LET): Enclosed fixtures only, Light Center Length (LCL): 5.000 cm, Maximum Overall Length (MOL): 8.2500 cm, Mean Lumens [Avg]: 12400, Mean Lumens [Typ]: 13500, Mercury Content: 31.000 mg, Nominal Initial Lumens per Watt: 76, Nominal Length: 8.250 cm, Open Circuit Voltage (peak lead ballast) [Min]: 540 V, Open Circuit Voltage (RMS lag ballast) [Min]: 382 V, Picograms of Mercury: 229.6 pg, Product Technology: High Intensity Discharge, Rated Life [Avg]: 6,000 h, Rated Life [Typ]: 10,000 h, Wattage: 250GE HID (High Intensity Discharge) lamps provide high efficacy and low operating cost. The HID is generally the most efficient light source. Better efficiency almost always means lower operating cost. They also have a long life. Most HID lamps have life ratings that are better than incandescent lamps and similar to fluorescent lamps. An HID lamp produces high light output from a relatively compact source. Like incandescent, it is a "point" light source, which allows for good optical control. Light bulb efficiency is measured in lumens per watt (LPW). Rated life for HID lamp life depends on the number of hours per start. The combination of high efficiency and long life makes HID an ideal light source for many commercial and industrial applications. For product questions regarding GE Lighting products, please call GE Hotline 1-800-435-4448, Monday – Friday, 8:00 a.m. - 6:00 p.m. EST Follow the recording prompts or ‘stay on the line’ to speak directly to a customer service rep.