 The CS Jian is made from a blend of polymers that make it both durable and flexible.It was designed to be as close to a traditional metal jian as the materials make possible, while still retaining the safety advantages of a practice sword made of a softer, lighter material than steel.They are promoted as an improvement over the wooden practice jians that have been used traditionally, since wooden jian vary greatly in quality and balance, and are not as flexible.