They jump from a tall building that reaches to the sky (in fact, you see clouds below the jumping pad in one part of the video) and then do crazy things in midair. Moments before hitting the ground, they open their parachutes.
To most of us, this is probably torture, but to them it’s pure ecstatic fun. To us, the question probably is, what if the parachute wouldn’t open? To them it’s probably, how much longer can they keep it closed?
See the madness of it all in the video!