Ruger 57 Optic Base Adapter Plate - JPoint SIG Sauer and Shield Sight Black. 7 pistol. The plate is precision CNC machined from 6061-T6 aircraft aluminum with a matte black hardcoat finish for strength and durability. Simply place the adapter plate onto slide and secure it using the two #6-32 screws provided. Tighten the screws firmly (30-50 in-lbs.) using a Torx T-15 wrench (not included). Install the optic onto the Adapter Plate by following the sight manufacturer's mounting specifications (sight not included). The Adapter Plate is 1.700in long x .975in wide and weighs .2 ounces. Specifications for Ruger 57 Optic Base Adapter Plate: Manufacturer: Ruger Red Dot Sights-Footprint: RMS Optic Cut: Ruger 57 Optics Ready Fabric/Material: Aluminum Color: Black Finish: Matte Condition: New Package Contents: Ruger 57 Optic Base Adapter Plate (jpoint Shield Sig ) Ruger 57 Optic Base Adapter Plate jpoint Shield Sig