Picatinny Rails For Ruger~ 10/22~ Rifles
Tough, lightweight aluminum rails feature Picatinny slot spacing for fast, simple changes to eye relief, plus greater flexibility in scope choice. Three height choices fit various objective sizes, or improve cheek weld. Extends over the barrel, or can be reversed to better position optics with shorter eye-relief. .750" model has an open sight channel that lets you use the factory sights. Uses the factory-drilled scope base holes, with no permanent alteration to your rifle.
Big Book Catalog, Issue:67, Page:251
SPECS: Aluminum, hardcoat anodized, black. 6-5/8" (16.2cm) long; .375" (.95cm), .500" (1.3cm), or .750" (1.9cm) tall.