This convenient box contains seven varying sizes of our durable stainless steel jump rings. The 4 and 5mm rings are 20 gauge, while the 6, 7, and 8-mm rings are 18 gauge. Additionally, the 9 and 10mm rings are 16 gauge. This assortment covers all of the different sizes needed for various applications in your jewelry making. Each box contains a total of 1410 pieces separated into separate flip-top compartments for easy organization.