8 pieces black 3M polyurethane anti-gravel film, thickness 380µ These self-adhesive protectors for your MTB are based on 3M's top-of-the-range, high-tech black film. Extra-thick (380 microns) and specially designed to absorb gravel and chain shocks, this film also protects against scratches and abrasion. Its texture makes it resistant to all attacks. The different-sized protectors are designed to protect the most exposed parts of your bike. You can put them under the downtube to protect against impacts, on the chainstay to protect against hits from the chain, and at the various points of contact with the casings.