Hi Phill,
This is the website of the original designer:
https://4stablestick.com/about-us/?lang=en
The Rudolph one is a good copy with a few improvements like the foam padding on the legs that stop the noise and make it easier to carry on cold days.
It also seems to extend and retract better than mine, although mine is an older model. Yes you can shoot from a chair if you want. I am only using it for possum shooting here in the north Island , but if I lived in south Island on the flat land and open country I would use one definitely .