Multi-Slot Bases are designed for specific models of firearms and provide an additional 1" of forward length for more mounting options. The multi-slot bases are compatible with Picatinny or Weaver style rings. An integral recoil lug, no slip/strip Torx screws round out the features of these tactical bases. Model Multi-Slot Base Style Extended Pieces 1 Material Aluminum Mount Type To Receiver Rings Included No