Tex from Hawaii was absolutely correct, sent for the DVD and other material for teh Crimson trace, and one of theinstructors speaking on the DVD said yur foinger would block te aser beam if it was in the proper position until you were ready to fire. This helps prevent the one thing people have eld against laser sights, that they give away your position. If it is dark enough to worry about giving away your position, it is too dark to be launching deadly projectiles around wily-nilly. try sending to Crimson trace fortheir information package, instead of lstening to people who do not know the product.. most of them here know it, but a few don't.