GBRS Group Hydra V2 Mount Kit

The Hydra V2 sits at a 2.91 inch optic centerline, which is roughly two thirds of an inch above the Unity FAST standard of 2.26 inches and more than an inch above the 1.93 inch mounts most shooters think of as tall. That number is the whole product. GBRS built the Hydra for shooters wearing gear that physically blocks a conventional cheek weld: helmet-mounted night vision, a CBRN mask, an active headset over a plate carrier. At 2.91 inches the optic comes to the eye with the spine vertical and the plates square to the target, rather than forcing the head down and forward onto the stock.

The V2 body is 6061-T6 aluminum with a Type III Class 2 hardcoat anodize, and the hardware is where GBRS spent the money: a 17-4 PH stainless clamp bar in H900 condition with a Melonite QPQ finish, matching stainless screws, and passivated black oxide 18-8 washers. Recommended clamp torque is 45 inch-pounds. Above the optic cradle sits an elevated MIL-STD-1913 platform for mounting lights, lasers, thermals, or a second aiming device directly to the mount instead of eating handguard rail space, which is what makes it useful on short PDW and SMG-length hosts where there is no room left up front.

The mount is optic-specific rather than universal. GBRS machines separate builds for the Aimpoint Micro T-2, Aimpoint Duty RDS, EOTech EXPS, EOTech XPS, and Trijicon MRO, each in Black or FDE, and weights run 6.1 to 6.5 ounces depending on which one you order. Two things to know before buying: a magnifier will not co-plane with this height unless you add GBRS's own 2.91 FTC mount, and GBRS sells the Lerna, the same mounting system minus the elevated accessory platform, for shooters who only want the height. Everything is designed, manufactured, and assembled in the United States.