The SureFire 623LM replaces the original forend of your Mossberg 590 shotgun, or your Mossberg 500 shotgun with a 7 ¾" forend tube. Compact 6-volt (2-battery) system features a virtually indestructible LED emitter focused by a TIR lens, which produces a brilliant beam optimized for close- to medium range applications. Two switches are integrated into the forend: a momentary-on pressure pad switch (right side) and a constant-on rocker switch (left side). The 623LM generates 200 lumens of output and has a tactical runtime of 2 hours per set of batteries, with gradually decreasing output afterward. The tough polymer body features a molded-in high-friction pad for enhanced grip in wet or cold conditions. Fits: Mossberg 590, or Mossberg 500 with a 7 ¾" forend tube