Durotest Compact Fluorescent Bulbs, Durotest Vita-Lite, Durotest Aurora VI, and Warm Tone 2700K. Durotest screw-in base fits all standard medium base screw-in sockets (E26). Durotest Vita-Lite Spiralux are excellent for pet lighting, and color matching (high color rendering - 5500K, 91 CRI - color rendering index.) NOT DIMMABLE - Do not use in dimmable circuits. Durotest compact fluorescents have a 12 month warranty. Durotest also has incandescent lamps, and Durotest Code Beacon.