Opie, what are these going onto?
Flush Mount D-rings or Surface Mount D-rings.
http://www.gemplers.com/product/173...=173153&ef_id=UFUsXgAABxa4Gk0c20120921011126s
Ive seen these. Far bigger than needed for a tie down on a sleeping platform. They require a 4.5" hole to sit down in. Maybe some smaller ones.....