FEATURES:-Machined from 6061-T6 extruded aluminum-Silver anodized finish-For Ruger 10-22, 10-22 Takedown-Lowered to allow for use of rear sight with mount mounted-0 MOA-Center Spread: 2.57"*-Overall Length: 4.645"-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 0.95 X 3.40 X 9.05Height 0.9500Width 3.4000Length 9.0500STYLE PICATINNYFINISH BLACK MATTEMATERIAL ALUM ALLOYTYPE OF RINGS NEEDED MIL-STD 1913 PICATINNYRINGS INCLUDED NOTHER FEATURES: MADE IN USA