What Is That Contraption?

Ok, let's see if you can guess what's in this picture (the big yellow thing!)
I actually own this, and have it at my campsite, or as I like to call it, my "Summer Residence"  - sounds fancier.
I haven't got it working yet (that's called being a bit lazy) but it is on my "To Do" list.
Any guesses what it is?
Comment below...