I spotted this GIF, and thought this might be a new invention from China:
I was wrong. After some digging, I found it's called the Mini Max Stool and was designed by Israeli inventor Yosef Zaifman. Zaifman runs Safrut, a company that produces injection molds, so he knows plastic (in this case, polyamide) well.
The design is quite clever: The body is made from 120 segments that are light enough--and strong enough--to lock into place with a twist, yet still support 260 lbs. (140 kg). While it can extend up to 16" in height, it can be set to any height you choose below that.
There's actually a little spring inside--not to support the sitter's weight, but to provide just enough tension on the interlocking segments that they don't pop loose. To get them to disengage, you rotate the top. Once it's all closed up, magnets keep it shut.
The stool itself weighs just 2.42 lbs. (1.1 kg). If you add the optional padded seat, that adds another 0.22 lbs. (100 g) to the weight.