Fortis F1™ Optics Mount is designed to work in conjunction with Aimpoint's popular Micro H-1, or T-1 optics. The F1™ Optics Mount is designed to attach to your flat top upper receiver. Its lightweight low-profile is one of the lightest designs out there at 1.1oz. The Fortis F1™ Optics Mount features an innovative design by extending the optic forward for faster target acquisition. It secures to any MIL-STD-1913 Picatinny Rail with two slotted machine screws. Offering a lower 1⁄3rd to your back up iron sights for a larger field of view. Features: One Piece Billet Design Slotted Screws Attachment Aircraft Grade 6061-T6 Aluminum Military Specification Type III Hard Coat Anodized Light weight 1.1oz Made in the USA!