FEATURES:-Machined from 6061-T6 extruded aluminum-Matte black finish-For Thompson/Center Encore-20 MOA-Center Spread: 0.838"*-Overall Length: 5.488"-Mounting Hardware: Hex head screws & wrench provided-Installation: EGW recommends 20 inch lbs. of torque & a drip of blue Loctite*The center spread is the distance between the two middle holes, center to center, on your receiverPRODUCT SPECIFICATIONS:Dimension 0.90 X 3.45 X 8.30Height 0.9000Width 3.4500Length 8.3000STYLE PICATINNYFINISH BLACK MATTEMATERIAL ALUM ALLOYTYPE OF RINGS NEEDED MIL-STD 1913 PICATINNYRINGS INCLUDED NOTHER FEATURES: MADE IN USA