Waterproof zipper, watertight zipper, airtight zippers 1) High quality 2) Competitive price 3) N3,N5,N8, ... by the TPU (thermoplastic polyurethane). When the zipper teeth are closed, the peripheral TPU (thermoplastic polyurethane) of the zipper teeth is ... and alkalis (normal temperature)Good Waterproof zipper, watertight zipper, airtight zippers