These premium quality iron rings are brass-plated to keep them from rusting and to keep your fingers clean while working with them. The welds have been filed so that there are no rough edges. They can also be used to make mandelas.
The measurements are the outside diameter. For example, the inside measurement of the 2" ring is 1 7/8". Most of the rings are made from 1/8" thick wire. The 27" ring is 1/4" thick.