KAEZI 85 Watt Studio Light Bulb 5500K CFL Day Light. Long bulb life of appr. 6,000 hrs. Dimensions: L: 10.5"; W (Diameter): 3.9"; Length socket base to top of ballast: 4.5"; W (diameter) of socket: 1". Daylight color temperature of 5500K Super bright with 4250 Lumens @ 1m Standard USA E26 base screw-in sockets