Just like the message says. I bought this for my Glock 19, but decided to sell the pistol before the light even arrived! I paid $149 + $10 shipping. I'll let this go for $125 shipped.
"Introducing the all-new M3X, where the "X" stands for X-treme. With 125 peak lumens AND 1-hour continuous run-time, the M3X's Shock-Suppression-System enables 30% greater white light output (vs. standard M3) without sacrificing overall performance. The enhanced mil-spec design allows the air-tight M3X to be exposed to the world's harshest environments, be it blinding desert sand storm or swimming 66 feet under salt water."