The Viridian R5 Gen 2 green laser sighting system for the M&P Shield 45. This laser sight is easy to install and blends seamlessly into the trigger guard for invisible profile and smooth draw. Viridian's green lasers utilize a 510 to 532 nm wavelength range creating an optimum target dot that is up to 50 times brighter than red lasers. It features two modes of operation: constant and strobe. New features of the gen 2 models include 3X more battery life (up to 5 hr) and an instant-on ambidextrous, inside the waistband (IWB) holster with automatic laser activation. Made of microfiber, this holster is more comfortable and durable than the previous models. The instant-on activation ignites the laser the moment you draw. No buttons, no squeezing, no doubt. When you draw, it's on.