The Viridian C5L-R is so tiny, it tucks neatly between trigger guard and muzzle, with no overhang, and will work with virtually any railed gun. 100 Lumen taclight, with the ELITE RED LASER with Advanced 635 nm wavelength, has a stronger, brighter targeting dot for greater accuracy and intimidation. Ultimate indoor/low-light performance. Combined with the TacLoc ECR Instant-On Holster- the package is complete- batteries included. Drawing the Viridian from the TacLoc ECR- Instant-On holster releases it smoothly and instantly ignites your laser automatically, the second you draw. It's the most advanced, most effective carry setup you can get. The complete package for your favorite gun.