Crimson Trace Corporation Hi-Brite LaserGrip, Fits S&W J Round Butt, Rubber Wraparound, Red Laser 01-4600-1 LG-350 Lasergrips(R) are an enhanced laser sighting option for Smith & Wesson J-Frame (Round Butt) Revolvers offering excellent comfort for shooters. This model features a front laser activation button" and boasts over 4 hours of battery life from (2) 2032 Lithium batteries. User-installed in moments by replacing factory grips" the unit is completely user-adjustable for windage and elevation. LG-350 Lasergrips feature the Crimson Trace ShockStop(TM) system" which couples soft" anti-vibration material and a cushioned grip to reduce recoil while increasing shooter comfort and accuracy.