ALZO 85W Joyous Light Full Spectrum CFL Light Bulb 5500K, 4250 Lumens, 120V, Daylight White Light, Extra Large THIS IS AN EXTRA LARGE BULB that will not fit most table or floor lamps; see diagram and size comparison in image section; dimensions: length: 10.5 inches; width (diameter): 3.9 inches; width (diameter) of socket: 1 inch; fits all medium-base E27/E26 sockets Crisp, bright white light ideal for reading and tasks that require visual accuracy; CFL bulb has natural daylight balanced color temperature of 5500K Great for starting plant growth Generates very little heat; all ALZO Joyous light bulbs are flicker-free; energy saving, uses about 1/4 of the energy of a comparable Tungsten bulb, with 4250 Lumens output at 120V, with CRI of 91; about 6,000 hours bulb life Important: ALZO CFL bulb life is based on the bulb in an open air fixture with sufficient ventilation; when ALZO bulbs are installed in fixtures that lack adequate ventilation, the life of the bulb will be reduced.