Ruger Standard, Ring, 30mm Medium(4), Matte Stainless Finish, 4K30HM, Sold Individually 90318
Specifications:

Type	Ring Single
Tube Diameter	30mm
Height	Medium
Size	Accepts up to 42mm
Finish	Silver
Style
Material	Stainless Steel
Style Description
One or Two Piece
Adaptor Type
Mount Type
Lock Type