Machined aluminum mount allows you to mount the Sniper Tool Designs Angle Co-Sine indicator directly to your Picatinny base. Will fit any M1913 MIL STD mount, attaches with 2 soft point set screws so it will not mar your mount. Also fits M16/AR-15 flat top rifles. Weighs less than 1/2 oz. Anodized black.

GEN I centers the ACI dial ABOVE the picatinny rail
GEN II centers the ACI dial BELOW the picatinny rail

Please look at the photos for reference.