To adopte tri-phosphor glass tube with high light effciency of 60lm/w, a ra of 80-82 and long life time of 8, 000hrs No noise, no flicker, low harmonic, anti-interference, and eyes-care during working Saving 85% more energy than incandescent bulbs With pbt cap, the material of fire resistance Two color temperatures(2, 700k/6, 400k) for choice Lamps can work under -30íµtemperature Base: e26/e27/e40 Tube diameter: 14.5mm/17mm, 20pcs/ctn Operating voltage: 110v-130v/220v-240v/50-60hz