Gauge: 2g(6mm),0g(8mm),00g(10mm),1/2"(12mm),9/16"(14mm),5/8"(16mm),11/16"(18mm),3/4"(20mm). Material: High Quality Surgical Steel. Sturdy and Durable, Corrosion Resistant. Simple and Generous, Comfortable and Smooth Surface, Give You a Wonderful Wearing Experience.