1-Black, interlocking mushroom-shaped heads (250 stem density per square inch) provide strong, reliable and durable fastening that can be opened and closed multiple times 2-Mates with Type 170, Type 250 or Type 400 stem densities to provide different strength combinations 3-Clear, acrylic, tape bonds well to a variety of substrates including metals, glass and plastics such as acrylics, polycarbonate and ABS 4-An alternative to screws and bolts, this hidden fastener provides a snug fit and smooth aesthetic appearance