Target Scope Mounts 6-40 Thumbnut for Unertl Standard Scope Rings (Eaches). Reproduction. PreviousStandard Block. Multiple Heights. 6-40 Thumbnut for Unertl Standard Scope Rings (Eaches). Reproduction. 6-40 Thumbnut for Unertl Standard Scope Rings (Eaches). Reproduction. $15.00 Fits standard Unertl scopes. Quantity: Add To Cart Facebook0 Twitter