Leupold designed these ring mounts in various sizes so you can mount any Leupold scope on a Ruger #1, M77, or 77/22 rifle. Machined from solid steel for critical tolerances and all around good looks, Leupold Ring mounts offer greater mounting flexibility for these Ruger rifles. Manufactures Website Address www.leupold.com Warranty Information Full lifetime guarantee. If any product has defects in materials or workmanship, Leupold will, at their option, repair or replace it free. Even if you are not the original owner.