This is a crazy, crazy tight ring size. The closest size matches in Spiderchain metal rings would be either 8:12 (inch sizes) or 3M12 (millimeter sizes). However, I don’t actually make those sizes because they’re insane. Spiderchain rings made with 12ga wire will match the gauge of these D14 rubber rings quite well, but you won’t be able to fit two metal rings through unless you choose something a lot thinner! (crazy, insane size…)
The aspect ratio for D14 rubber rings is 1.50 (wow!)
inner diameter = 3mm (roughly 1/8″)
“wire” size = 2.00mm (0.079″)
A few examples using D14 rubber rings:
Happy (stretchy) chainmailling!