I bought my windows from Red Neck (15 x 24) following a lead MadJack offered and figured I'd better get these clamp rings as well "to ease the installation".
The guys at the parts counter at Red Neck were so confused they ordered another set, but they weren't much help when they came in. The pre-drilled screw holes seem to line up perfectly with the edges of the window, so if I screw the ring directly into the widow flange all the holes will be 'c' shaped, none biting into the flange entirely. I've never seen a clamp ring installed, so maybe I'm totally off track....
MadJack, are you out there somewhere???
