Available in A4 or A5, the SteelBack is a steel u-channel spine with a leather look or metallic finishing for use with the Unibind thermal binding machine. Itメs tear off paper guide sheets allow you to add your own front and back covers or Unibind Transparent CoverSets and HardBook CoverSets. This gives you the flexibility to produce A3 and A4 landscape documents as well as A4 and A5 portrait. Once bound on a Unibind machine the unique patented polymer guarantees a secure, long-lasting bind that allows your document to be easily edited. The SteelBack is available in various sizes which allows you to bind up to 340 pages in A4 and 100 pages in A5.