I've got a similar thing, "the red exerciser". It's like a stool you sit on with handles at the side and you do ab twists on it, you can tighten or loosen the resistance. It's really easy exercise, and really works. It folds down flat and fits right under the bed and can be put up in about 2 mins. What's more, it cost just £24 and that included the postage and packaging. This does look much more cumbersome, hard work to do, and ridiculously expensive!