13 superbright white LEDs in a 360 degree radius replace the common #1157 single filament that are probably in your bike right now. No modifications are necessary - installs just like the regular bulbs. LED bulbs have a much greater life span and will withstand vibrations better than all conventional incandescent bulbs – so you’ll have less chance of being caught with no taillight or turn signals. Newest LED technology is 50% brighter than early LED’s, but still draws less juice and produce less heat. This may be the last taillight and turn signal bulb you’ll ever buy. 12V.