Advantage: FC8T9/841 22W cool white round fluorescent bulbs 6400k, 1350 lumens, saving bulb. 8inch Circular Light Bulbs: 8 inch t9 type 22 circline light bulb, 4 pin G10q base, CRI80, soft cool white 6400k. FC8T9/CW Cool White plus 22 watt circline Fluorescent lamp: 16,000 hours lifespan working with matching and reliable electronic or magnetic ballast. Application: replacement for fc8t9/cw 22 watt 8 inch round t9 fluorescent circular light bulb in ring ceiling fixtures bedroom, bathroom, kitchen, hallway, laundry room, office.