LaserMax CenterFire Red Laser Sight (Fits Smith & Wesson J-Frame 642, 442, 637, 638 & 438) n/a Imported Tough reinforced nylon design offers superior integration with firearm frame Easily programmable for steady or high-vis pulsed beam 10 minute automatic time-out prevents inadvertent battery drain Ambidextrous TAP ON/TAP OFF switch reinforces safe firearm handling 3R Hazard class Less than 5MW