you have to open the individual scope page, (can't use the add to cart button from the list page) Then select the rings you want and add to cart.

go here http://swfa.com/SWFA-SS-16x42-Tactic...pe-P53715.aspx

Then click on the ring you want below the add to cart button, then hit add to cart.

It's goofy as hell, and took me a trip to their FB page to figure it out.