Featuring two levels of tactical illumination, ambidextrous switching, a slender ergonomic design, and legendary SureFire reliability and durability, the DSF-500/590 is the ultimate WeaponLight for Mossberg 500 or 590 shotguns. The compact, lightweight system replaces the weapon's original factory forend and features a recoil-proof LED that generates 600 lumens of blinding white light at maximum output, or 200 lumens with twice the runtime on its high setting. The LED's light is focused by a precision reflector to create a smooth, wide beam. The DSF-500/590 features large, tactile momentary and constant-on switches on both sides for precise control by left- and right-handed shooters. It also features an integrated system-disable switch to prevent accidental activation during transport, storage, or stealth operations. A lightweight but strong aluminum module protects the optics, LED, and sophisticated electronics, minimizing length with side-by-side placement of the two lithium batteries that power the system. The module has a Mil-Spec hard anodized finish to protect against scratches, abrasion, and corrosion, while O-ring and gasket seals keep out moisture, dust, and debris. The slender forend body is made from extremely tough polymer and is textured for a secure hold and features large, tactile momentary and constant-on switching on both sides. The DSF-500/590 is compatible with any 500 or 590 shotgun variant with a 6.75" forend tube (magazine tube). An included internal spacer provides a proper fit for 7.75" forend tubes.