NAKED BULB NK-921-250CW LED Replacement EMI Suppressed Vented Bulb, Wedge T5 Base &ndash; i.e. (921 Type), 250 Lumen 8-20Volts Cool White 60,000+ hour life expectancy, made possible by Patented Vent System that allows the bulb to run cooler unlike others; The Bulb base is a Wedge T5 Base  i.e. (921 Type); 8-20 volts DC; the wide-range voltage is designed to withstand RV power fluctuations that damage other bulbs; The Naked Bulb Runs Cooler, is more Energy efficient and eco-friendly than the incandescent it replaces, contains no mercury: The only LED Bulb that is EMI SUPPRESSED so as not to wipe out TV or radio stations;