Egw scope base ruger 10-22 picatinny rail silver FEATURES:-Machined from 6061-T6 extruded aluminum-Silver anodized finish-For Ruger 10-22-0 MOA-Center Spread: 2.57"*-Overall Length: 6.276"-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 receiver Other Features: Made in usa