This P21/5W mini indicator lamp has dual C-6 filaments, operating at 13.5 and 13.5 volts. The primary filament's average life is 300 hours. The secondary filament's average life is 2,000 hours. It is typically used as a tail light or brake light in foreign cars.
Average Lifetime: 300/2000 hours.
This is a twin filament bulb which produces a very bright light to help alert other road users when breaking to reduce the risk of rear end collisions. They help to provide 50% more reaction time to drivers behind you. If this is used as a reversing light it will give you far the bulb also uses very low power consumption only 5W helping the product to last longer.