FAB Defense designed the TAL-4 Tactical Vertical Foregrip to improve the handling of your weapon. This foregrip features dual-sided pressure switch housing, a waterproof, a quick release mechanism, a secure bolt locking system, and an anti-rattle storage compartment for two CR123 or AA batteries. It is constructed of a lightweight fiberglass reinforced polymer with a quality non-slip design. The TAL-4 Vertical Foregrip is compatible with all 1913 Picatinny or Weaver rails (min. 2.55" long).Advantages:Quality non-slip designDouble side pressure switch housingWaterproof, anti-rattle storage compartment for two CR123 or AA batteriesBoth quick release mechanism and a secure bolt locking systemDesigned to fit on all 1913 Picatinny railsDurable & Lightweight fiberglass reinforced polymer constructionUser installed-no modification or gunsmith required