Approximately 29x9.4x3mm brass plated base metal hinged donut bails for jewelry making. These bails have a 16mm inner diameter, and are easy to open and close. Plated over zinc. Fits up to 3.2-3.6mm chain or cording. For use with 40mm round gemstone donuts up to 6mm thick. Once the interlocking loops are strung onto chain or cording, the donut is securely locked.
I really like these, great price, hinge & locking mechanism works well. Unless I really wanted to bend & manipulate the bail it DOES NOT work with the 40mm donuts that I have from R&T. Works great with 30mm ones, however, so am just mareketing the bail with the smaller donuts.