Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Great product--precise settings

...I agree with the other reviewers, very solid, instructions minimal, not portable. A nice feature is that the degree of incline is regulated by steel bars with adjustable quarter inch pins, not a nylon strap. Which means precise control, as you gradually get used to steeper settings, and also different people could easily use the machine and have their own settings....As regards use of such a machine, I believe it is possible to injure oneself easily if one's back and stomach muscles aren't strong. Especially if older it's probably good to build up strength with the yoga poses: locust and cobra first, and begin very gradually with the inversions.