Razor wire or barbed tape is a mesh of metal strips with sharp edges whose purpose is to prevent passage by humans. The term "razor wire", through long usage, has generally been used to describe barbed tape products. While razor wire is much sharper than the standard barbed wire, it is named after its appearance, but is not actually razor sharp. Concertina Razor Wire is one typical kind of razor wire. Concertina wire or Dannert Wire is a type of barbed wire or razor wire that is formed in large coils which can be expanded like a concertina. In conjunction with plain barbed wire and steel pickets, it is used to form military wire obstacles. Our concertina spiral razor wire is made of 0.5mm thick hot-galvanized steel sheet and 2.5mm thick high-carbon galvanized wire. These coils are compressed for transportation, and then stretched for use.