This is a Crimson Trace Corporation LaserGrip known as the Lasergrips, model LG-306.
LG-306 laser sights for Smith & Wesson K & L-Frame revolvers feature a comfortable rubber overmold on the Lasergrips(R) that is slimmed down for concealed carry ease. The laser activation switch is located in the front of the revolver" making activation "instinctive" when you assume a normal firing grip on the revolver.
Features:
Pressure activation
Red laser
Factory sighted at 50Ft
.5 inch diameter at 50 feet
