This is the Viridian CR123A Battery 3-Pack for use in Viridian X5L (Gen 2) Laser. CR123A Lithium size for Viridian X5L (Gen 2) and many other tactical accessories, such as flashlights, etc. Viridian tactical batteries deliver the power to prevail when it counts. Advanced lithium technology, matched to the demands of tactical tools, ensures stronger, longer-lasting energy under all conditions. For performance you can trust under fire. For laser sights, weapon-mounted lights and tactical flashlights. Maximum life for instant readiness. Maximum power delivery start to finish. Low-impact, recycle-friendly design.