I was able to pick up this NSD Powerball for $17 here on Amazon and what a steal!It probably took me about twenty minutes to get the motion down and, to be honest, I thought I got a broken one for the first ten because I couldn't get it to do anything. The best advice I can give is not to fight the motion you feel in the gyro. It's not about just spinning your hand around as fast or as hard as you can, it's about matching and then revving up the cadence of the gyro. It's fascinating to watch it switch directions when changing hands or rotation and equally amazing watching it jump about when you've ceased moving and the gyro just spins and spins and spins.As far as the exercise goes, I can certainly feel the burn and wish that I was able to keep it going for longer without becoming sore. I got this to help strengthen my hands, wrists, and forearms, which get abused daily as a computer tech and also an avid landscaper. I can certainly see this helping, but I have to be careful not to overdo it, as it honestly is quite addicting and fun (not really a valid complaint :)My only con is cheap construction. While I don't think it's going to stop working anytime soon, mine makes a lot of squealing noises at low speeds. Once revved up, it's no longer audible and you can only hear the whir of the gyro. At the price point, it's not really something worth complaining about. Whenever this one wears out, I'm quite sure I'll go for a nicer model. Very satisfied.::EDIT::04/17/13About a month with the NSD Gyro and I am feeling amazing. The first three weeks were spent exercising one day and being sore for two, and again, and again. I'm happy to say that after a week or so, I began to have this warm tingling feeling spreading from fingertip to elbow while I lay in bed at night. My god, that's blood circulation! Within the last week I've been able to make it an every or every other day affair. I like to put in earbuds and either play air drums, or dance around a bit with the gyro. It really is fascinatingly fun to go with a good beat. I like to get rhythms going where I can swing the gyro around half speed on the down beat to mix things up. My highest praise goes to the fact that the exercises can be as easy or as hard as you'd like without any need to change weights. I tend to start out with a wide, slow arc holding it as a baseball, switching rotation clockwise and counterclockwise before switching hands, just to warm up. Then I speed up a tad, holding the gyro like you would the end of a jump rope: clockwise, counterclockwise, switch hands. Then I grip the gyro like I'm holding a glass of water and I tip it forward and back, forward and back (this is an amazing workout...if you can manage to switch rotation of the gyro on this one, kudos...it's hard). Then I hold it by nothing but my fingertips and again pretend that I'm holding one end of a jump roap: clockwise, counterclockwise, switch hands. This is when I go back to the original slow arcs, holding it as a baseball. Once I've loosened up a bit, I do it all over again, but usually at double speed, or close to it. Realistically, you can make this spin in almost any way you can imagine, as long as you go with the flow :)It still squeaks when slowing down, but shows no signs of wear. Very impressed.

I had never even heard of these before Amazon started bombarding me with ads for them. Normally that makes me want to avoid the product, but I ended up buying this mostly out of curiosity because I couldn't quite understand how it was supposed to work. I'm so glad I did. This thing is one of my favorite tools ever for working on grip and forearm strength.I really like that you can use it in multiple different ways and that it works multiple different areas, depending on how you use it.The instructions that came with it were not very clear in describing how to use it, but that's not a big deal. The description right on the Amazon page is much clearer and is what cleared it up for me.I love that it's small and easily portable so you can use it literally anywhere. Works your whole hand and forearm, and in different ways depending on how you use it and at what speeds. And while it can be much more intense at fast speeds, you can also get a really intense workout at very low speeds. The key is to experiment with different grips and spin patterns and directions (changing spin direction is as easy as a flick of the wrist and barely noticeable). Takes maybe only 10-15 minutes of experimenting and practice at the beginning to really get a feel for what you can do with it.It does squeak a little at higher intensities, indicating that maybe the quality isn't the best, but whatever, I've had it for about 8 months now with no issues. Even if it craps out after a year, it's been so useful that I'd gladly buy another one.

UPDATE AS OF 8/26/2013 at the bottom of review..I bought this device to re-strenghten my hands after neurosurgery.Previous to my surgery, I worked with my hands(mechanical) quite a lot, did indoor rock climbing, previous weight lifting and in general use my hands quite a bit, so I think I can accurately describe whether or not this is a good workout.I would say after surgery I lost about 75 percent of my strength.I used this for a month or two, and my grip strenght steadily increased, as well as my forearm tone.I can't give you an accurate number on how much grip strenght I regained in pounds of force, but I can tell you my grip is pretty much back to normal.I stopped using this device months ago, but noticed what I thought was hand weakness again, so I started using it again. I can tell you the improvements happen right away from day to day, and if you do too much, your fingers, hands and forearms will definitly burn.This device works.Ease of use:I can tell you some people have a real hard time with this. You have to match the rythem of the device and spool up the Gyro. Some people can't seem to learn how to do this for quite a while, but I can tell you that after you learn how, it is second nature.Durability:This is where the device looses a star. I find that after treating pretty carfully, it is getting a little less smooth to gryo up, and it is getting a little sloppy at the lower speeds. To be fair, I did drop it once.Cost:I believe for what you get, it is reasonable.Fun factor:Much more fun than any other hand exercise I had done when I was a regular weight lifter. Hand exercises are generally pretty boring. You can't see results in your hands, and unless you have a weakness preventing you from doing something, you won't notice. This however, is fairly fun, and quick to do.UPDATE:This device has helped me regain 100% of my grip strenght. The nerves healed sure, but this also worked in conjuction with the healing process. The effected nerves were in my cervical spine, which don't heal like peripheral nerves do, so it is quite inspiring that I got no only my grip strenght back, but maybe a little more.I can crush peoples hands now, and I have kind of thin, "piano" fingers. I have never had problems with my grip, but I am not someone who others would think would have a "strong grip". Before using this device, after surgery, I could squeeze someones hand, and they would say "seriously, are you really squeezing?" Not that I go around doing that, but I have asked my good friends to let me re-test my grip strenght on them.I would like to buy a hand Dynamometer, just to see how far I can go. The results are inspring, and like I said above, it really isn't boring to do.

excelente producto

Great product. Simple and efficient.

Já uso faz tempo,essa marca é a de melhor qualidade.

騒音が少なく、スムーズに回ります。購入前にYouTubeで回し方のコツなどを見たので、２回目で回せるようになりました♪複数の商品の動画を見ましたが、この商品はかなり騒音が抑えられているようで静かです。ひもが無くても、手のひらで回してからできるようになりました。腕の筋持久力を付けるのに良いかと思います。消防団に入っているのですが、渦巻き状態のホース２本を同時に運ぶときに、１本は肩に担げるのですが、もう１本は手で鷲掴み状態にして運ぶ必要があります。この状態で走る際に、腕の筋持久力が重要となります。当初、５０メートル程度しか持ち運べなかったのですが、この商品でトレーニングしたおかげで200メートルほど運べるようになりました。

So far good