The Ultra High Output Lamp Assembly P61 from SureFire is a specially engineered lamp that, when combined with its designated and carefully engineered reflector, will produce SureFire's brilliant and perfectly-focused beam. The reflector is either integral to the head of your flashlight, or part of the prefocused lamp assembly.
You can purchase either standard high-output replacement lamps for your flashlight, or optional ultra-high output lamps that nearly double the light output (available for most flashlight models). Ultra-high output lamps use more energy, and therefore deplete batteries more quickly.
The P61 is an ultra high-output replacement lamp with an integral reflector for the G2, 6P, D2, C2, Z2, and M2 flashlights. It delivers a 120 lumen beam for 20 minutes.