Ruger 90321 4B30HM Scope Ring Matte Black 30mm Medium
http://www.tandktactical.com/shop/736676903214-ruger-90321-4b30hm-scope-ring-matte-black-30mm-medium-13555
http://www.tandktactical.com/web/image/product.template/13555/image_1920?unique=880c94d
Designed to fit a scope with a 30mm scope tube diameter and a 42 MM objective diameter.
