This ring is about Men's Ring Size 15+, after metal shrinkage. It fits the largest finger on my rather large hands without a problem.
(UPDATE: I've made some changes that should get around that printing error Shapeways is now giving. I'll test it as soon as I have the money to buy new prints)
2.834 w x
0.956 d x
1.116 w x
0.376 d x