Talley Scope Mount/Ring Combo features a 1 tube diameter and Medium mount height (0.600) for Henry Big Boy lever-action rifles (specifically Models H006 and H012; excludes flat-top H009/H010). Crafted with a black anodized finish, this 1-piece unitized mount weighs 2.40 oz. Integrated ring and base design mounts direct-to-receiver via included #8-40 Torx screws and T-15 wrench to eliminate alignment errors. Safety Note Always ensure the firearm is unloaded before installing or adjusting any optics or bases. Verify proper torque specifications during installation. Improper mounting may affect accuracy and safety.