What is the difference between NSD Powerball and the cheap copies?

Or; "Why would I bother spending AU$ 59.95 on 250Hz NSD Powerball 'Pro' when I can buy a gyroball, or similar copy product for only AU$29.99?"

Two kinds of hand gyro exist on the market these days;

1. The first can be bought in the shops from under AU$20.00 / it is generally made in China and is a mass produced product, manufactured in quantities of hundreds of thousands each production run.
   
   In this gyro, iron axles and cheap plastics are the order of the day.
   
   These are generally a similar size to NSD Powerball and weigh approximately the same. However, that is definitively where all similarity ends.
   
   The key element of any hand gyroscope is its rotor.
   
   In the cheap copy product, the rotor is mass produced and is therefore not balanced in any way before being inserted into the outer shell which itself is then glued together. In simple terms, this means that as soon as you activate the gyro, the off balance rotor inside will begin to vibrate strongly and transmit shock waves into your hand and up along your arm the faster you spin the ball.
   
   As a consequence, these are often called "Vibro", "wrist" or "Gyro" ball or similar, by their manufacturer.
   
   Apart from limiting the actual top speed the rotor can reach (these gyros can generally reach maximum speeds or around 6000-9000rpm), it also means that your limbs are subjected to a most unpleasant 'shock' sensation at these higher speeds as the vibration from the off balance rotor becomes more intense the faster it spins.
   
   This might be acceptable if you have purchased it as a toy or a game for your children which you do not expect to last long anyway, but not much good if you are looking for an arm workout for sports or fitness purposes or some non impact rehabilitation for a damaged wrist or arm.
   
   
2. NSD Powerball - the second type of gyro on the marketplace and several generations ahead of the other versions, NSD Powerball is a tuned, precision product which has been hand assembled using materials of the highest quality and which features an internal rotor on a stainless steel axle which has been so finely and precisely balanced using advanced computerised jigs that it can reach speeds in excess of 16,000rpm without vibration of any description.
   
   NSD Powerball's primary focus is as a sports/fitness and rehabilitation instrument and succeeds in this aim as a result of its totally non impact properties. Each NSD Powerball is individually tested before being hand assembled to ensure 100% precision in every component - a time consuming process which adds considerably to the basic build cost of each unit when compared to the mass produced items described above but also one which guarantees superlative quality in the finished product when compared to the mass produced copy items.
   
   The outer shells in the NSD Powerball product range are also snapped together as opposed to being glued like in the copy gyro which allows each NSD Powerball to be easily and completely refurbished back to factory spec. in the event of accident or wear - the lifetime warranty offered on each unit allowing the user to request a new component, absolutely free of charge, as required.
   
   Finally, the 'Pro' NSD Powerballs are shipped with an extremely accurate inbuilt digital counter/speedmeter to allow the user record and monitor their speed and performance during each session - a valuable addition which ad's further benefit to the instrument and keeps it at the very top of its particular marketplace.

Summary:

Powerball features

1. Your new NSD Powerball is a superlative product which has been hand built from start to finish.
2. Each NSD Powerball is built around a stainless steel rotor axle using only the highest quality plastics.
3. Only the NSD Powerball has the record breaking 250Hz and 350Hz rotor included.
   
4. Before assembly, each rotor (the heart of your new NSD Powerball) will have been clinically balanced on a state of the art computerised jig to ensure absolutely zero vibration at any speed that a human being could be capable of spinning it at - consequently, NSD Powerball can reach speeds in excess of 16,000rpm without missing a beat.
5. All 'Pro' NSD Powerballs come complete with the current Accura Speed meter V2.0 to ensure precise registration of the rotor speeds achieved during a session.
6. The NSD Powerball is a serviceable product and spare parts can be obtained
   
7. Your new NSD Powerball is shipped with an lifetime guarantee against manufacturing faults.
8. Life expectancy - forever (if well looked after)
   

Copy Product Features

1. Mass produced in China
2. The rotors aren't balanced in any manner and so will struggle to reach speeds of 8,000rpm, at which point they are vibrating badly and make the whole experience a less than enjoyable one
3. Only one of the copies we have come across ('rollerball') has the option of a digital counter. On testing samples of this product, it was quickly established that the counter (a copy of the older Accura Speed V1.0 meter we used before the current model) was presenting completely inaccurate scores to the realtime achievement of the rotor and was found to be reading some 25% off the true [rotor] rotational speed. The other copies have no such facility.
4. Offered with a basic, conditional, factory warranty (if any)
5. Life expectancy - very low