Hammers .22 Crossbow Airgun Scope Rail Adapter Riser 3/8"-11mm Dovetail to Weaver with Stop Pin, Black Converts dovetail rails to a 9 slot Weaver rail Also works as a riser mount that raises line of sight by 0.571Inch Built-in pointed Stop pin and 3 clamping screws for extra holding power (needs to have predrilled receiver top to apply) Reversible side plate to adjust fit between 3/8Inch and 11mm dovetail rails Great for Use on .22 rifles, air guns and crossbows with dovetail scope bases