The Crimson TraceA(R) LG-420G LaserguardA(R) is a powerful green laser sight for the Sig SauerA(R) P320 pistol, (also known as the M17 in full-size and M18 in compact). The LG-420G is quickly and easily user-installed in moments and offers a front activation button powered by Crimson Trace's Instinctive Activation(TM) technology. The laser sight will provide two (2) hours of battery life with a single 1/3N Lithium battery and