Leupold's Standard rings are precision engineered to match up with STD 1-piece or STD 2-piece bases. Rear ring is secured by windage adjustment screws.
Specifications:

Type	Ring Set
Tube Diameter	30mm
Height	High
Size
Finish	Black Matte
Style
Material	Steel
Style Description
One or Two Piece	2
Adaptor Type
Mount Type
Lock Type