PROTECTED METAL HALIDE - Sunlite high intensity discharge lamps are perfect for outdoor lighting and commercial interiors. These energy efficient HID lamps offer exceptional efficacy, great color rendition, have a long service life and excellent lumen maintenance..HIGH INTENSITY DISCHARGE - This 400 watt bulb puts out a bright 33000 lumens of light. Color temperature is 4000K. Clear glass bulb..MOGUL BASE - Larger mogul base (E39) for use in street lights, parking lot fixtures, perimeter lighting, and other commercial and industrial lighting applications. Bulb measurements 4.7 inches diameter, 11 inches tall..PULSE START - These protected pulse start bulbs feature a long 15,000 hour average lifespan..ANSI CODE M155/O - This metal halide bulb is for use in M155/O ballast fixtures. Confirm ANSI Code to help determine the correct bulb for your fixture and the ballast it uses.