This GE PH211 light bulb (115-125V, 75W) is a 115/25 volt, 75 watt frosted incandescent light bulb for an enlarger head. Itis "A" shaped with a glass diameter of 2.6 inches, a screw basemeasuring 26 millimeters in diameter and an overall length of 4.9inches. It has a Kelvin temperature of 3000 and is rated at 100 lifehours. (GE40569)