The Kino Flo KF55 Fluorescent Light Bulb is balanced to 5500 degrees kelvin and for use with the Kino Flo Diva-Lite 200 and 400. Two bulbs are required for the Diva 200 and four bulbs are required for the Diva 400. Length: 21", Wattage: 55, Lumens: 4500.