Just another piece of gym kit, well yes but this one does actually work very well. Ok so it's limited, arms and upper body only but rather than say limited how about targeted? You're going to need some upper body strength to start with as the spring is quite powerful, strong hands also you wont want to accidently let go of this under tension althrough it does have 'safety' wrist straps. It's one of those bits of kit you can just pick and use any time any place, just two minutes and you can feel the burn, I do ten reps each at waist, chest and eye level behind head, then repeat. It's how you use it that matters, effort in equals results out! I've been using various gym kit for years and this is the first bit of kit I've been really impressed with and written a review about.