Very strong and durable material typically made from 87% copper and 13% zinc. Using 100% brass would render the zipper chain too No.3 brass zipper pin lock close endNo.3 brass zipper spring lock(4.5YG) close endNo.4 brass zipper spring lock(4YG) close endNo.4 brass zipper auto lock close endNo.5,No.8,No.10 brass zipper auto lock close endNo.5,No.8,No.10 brass zipper auto lock open endNo.5,No.8,No ...