From The Manufacturer:

DiMarzio ClipLock™ straps, with the world's most secure and unique guitar strap fastening system, are now available in Italian Leather. Their new Custom Italian Leather ClipLock™ Strap is made from thick Italian leather using special tanning process that makes it incredibly soft and flexible. It feels like an old friend the first time you wear it.

Cordura® is an abrasion-resistant nylon material often used by the U.S. military. It is an air-textured nylon fabric that is engineered for durability, strength, lightness and easy care. We chose Cordura® because of its feel. It differs from our nylon strap material in that the guitar stays in place instead of sliding.