Chansigong exercise is fundamental in taijiquan. It concerns two parts, one being the direct axis along the elixir field, the other being the level axis crossing the elixir field. Both of the two parts center on the elixir field. They are closely connected to each other in any movement. Taijiquan is variable, only when one masters Chansigong would he get twice the result with half the effort when practicing taiji.This product is manufactured on demand using DVD-R recordable media. Amazon.com's standard return policy will apply.