TangoDown Vertical Grip, Fits Picatinny, Black BGV-MK46BLK The Vertical Foregrip that started it all. The TangoDown BGV-MK46 has become the standard for US Military small arms" offering levels of utility previously unseen in this type of product. Rugged ergonomic design is complimented by premium heat and impact-modified injection molded polymers for long mission life. The BGV-MK46 is as at home on MK18s" M4s and M16s as it is on M32 40mm grenade launchers and MK 48 MOD 1 belt-fed machine guns.