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 design Double side pressure switch housing Waterproof, anti-rattle storage compartment for two CR123 or AA batteries Both quick release mechanism and a secure bolt locking system Designed to fit on all 1913 Picatinny rails Durable & Lightweight fiberglass reinforced polymer construction User installed-no modification or gunsmith required