Rockin Beads Brand, 400 Jump Rings, Silver-plated Brass, 12mm Round, 21 Gauge. Open 10.6mm Inside Jewelry Connectors Chain Links Sold Per Pkg of 400 Silver Plated Brass 400 per package 0.7mm thick 12mm outside 10.6mm inside Open not soldered Comes with Rockin Beads Size Gauge Card