Dipped in soft tacky butyl rubber to seal the injury. Quick and easy to install with a split-eye inserting tool. Inserts are not intended to be a permanent tyre repair. They are a temporary measure until the tyre can be properly repaired in a full service facility. NOTE: For a proper repair always remove the tyre from the rim and inspect for damage before installation of a repair unit or hole-filler material. Tool to use = open eye on side