This is Chen Style Lao Jia Cannon Fists form performed by a group of Tai Chi instructors who trained under one of the 4 Kings of Chen Style Tai Chi, Wang Xian. It's a nice demo of a form that more than any other sets Chen Style Tai Chi apart from the other main styles of Tai Chi. This form has frequent use of Fa Jing - the explosive power that is often not associated with Tai Chi as it is more associated with slow, graceful movements.