The Sightmark Tactical 30mm Fixed Cantilever Mount is a fixed mounted riflescope base compatible with 30mm scope tubes. This mount features a two-inch forward offset allowing the use of riflescopes requiring a greater eye relief and more comfortable cheek placement on AR-style rifles. The 30mm fixed mount is constructed of aircraft-grade 6061-T6 aluminum and finished in a matte black, non-reflective coating. Cantilever mounts make transferring your optic easy. This mount is perfect for installing and removing an optic from your firearm without losing zero. Includes 1.0" reduction rings.