This is a very effective brake light upgrade. TWO compact clusters of 8 LEDs (light emitting diodes) attach by self-adhesive to the outside of your brake light housing, or inside the housing on some models. When you use the brakes, the HYPER-LITES flash rapidly in bright red for as long as brakes are applied. The Dual Function HYPER-LITE adds an always-on red running light feature. Each kit has everything you need including clear instructions.