Stainless Steel rings come in 5 sizes with a standard 3.5 snap attached. The width is 15mm/0.5" and the depth is 4mm/0.2" on all. Inner and outer diameter varies as follows

A. 28mm/1.5" inner diameter

B. 30mm/1.6" inner diameter

C. 44mm/1.75" inner diameter

D. 47mm/1.8" inner diameter

E. 50mm/2" inner diameter