OttLite T18330 18w Replacement Tube Bulb, bulb type B •Superior image and color rendering •Low heat, low glare illumination helps reduce eyestrain •Energy efficient bulb rated to last up to 10,000 hours •Complete detail and color accuracy •For use only as a replacement bulb with specific OttLite lamps - bulb type B Need more information on this product? Click here to ask. Dimensions: 1.63″ x 0.63″ x 8.75″.