Is it safe to climb SRT on the Zig Zag with a rope wrench?

Is it safe to use the Petzl Zig Zag in an SRT setup with the Rope Wrench? What is the breaking strength of the Petzl Zig Zag and the Zag Wrench Tether? What forces are exerted on a rope and climber in different kinds of tree climbing accidents? How much force can the human body withstand? Watch this video and hopefully the tests and analyses shown here will help you make your own decisions. Thanks to Kevin Bingham () for providing the Rope Wrench used in the pull tests