UTG DNT06 scope mount base Attaches to RWS rifles with 11mm scope rail Fits any rifle with an 11mm scope base...either dovetail grooves or a raised rail Decreases barrel droop with 10" upward compensation at 30 yds Stops scope shift--forever! Scope base provides a secure foundation for Weaver/Picatinny mounts 4 hex screws firmly attach base to your Diana rifle Dual scope-stop pins to stop movement 0.68" saddle height 0.78" total height 1" wide 4.72" long 11 slots to accommodate various eye relief adjustments 3.8 oz. Aircraft-grade aluminum Includes 2 hex wrenches, hex screw and set screw Barrel droop is a common issue in some air guns, but it can make it difficult to use a scope. To get the most accuracy from your air rifle, mount a scope, but don't put it directly on the airgun's original rail. Instead, mount this great adapter, which offers 10" of upward compensation (at 30 yds.), and then mount your scope. You'll wonder how you ever got along without it!