ZipperStop Wholesale Authorized Distributor YKK&reg; SALE 36" Separating Zipper ~ YKK#10 Nylon Coil Zipper ~ 580 Black (1 Zipper / Pack) ZipperStop Wholesale Authorized Distributor YKK 100" Sleeping Bag Separating Zipper YKK#10 Nylon Coil Zipper ~ Black (1 Zipper / Pack) The slider runs on two coils on each side; the "teeth" are the coils. These zippers are thoroughly tested for strength and durability.