YKK 20" Jacket Zipper ~ YKK #5 Aluminum Metal ~ Medium Weight YKK Zipper ~ Separating Bottom ~ Black (1 Zipper) ZipperStop Wholesale Authorized Distributor YKK 20" Jacket Zipper ~ YKK #5 Aluminum Metal ~ Medium Weight YKK Zipper ~ Separating Bottom ~ Black (1 Zipper) YKK aluminum zippers are made from the highest quality metal. Thoroughly tested to ensure strength & reliability. Aluminum Teeth.