The 3M™ Dual Lock™ Snap Fastener Tape SJ3560 is made of transparent polypropylene. The smooth back has a clear acrylic adhesive, the top has 40 mushroom caps per cm² and when closed the flexible snap fastener is 5.8 mm thick. Our flexible snap fastener offers at least 50% of the original tensile strength after 1,000 open-close cycles.