Leupold Mark Integral Mounting System With 20MOA 1-Pc Base & 35mm Ring Co. From the Mark 1 to the Mark 4 each aluminum cantilever design mounts directly to the firearm's MIL-spec 1913/Picatinny to raise the scope and push it forward eliminating the need for risers or specialized optics with shortened eye relief. All Leupold products are tested to endure the rigors of the field and covered by the Leupold Lifetime Guarantee. Specifications for Leupold 176887 Mark Integral Mounting System With 20MOA 1-Pc Base & 35mm Ring Co: Manufacturer: Leupold Fabric/Material: Aluminum Ring Quantity: Pair Package Contents: Leupold 176887 Mark Integral Mounting System With 20MOA 1-Pc Base & 35mm Ring Co Leupold 176887 Mark Integral Mounting System With 20MOA 1-Pc Base & 35mm Ring Co