I got this today to exercise and thought I will share it with you. Its a good gadget for musicians, athlets and motorcycle riders 
POWERBALL
What is Powerball?
The Powerball is an exercise device. Developed in the USA, it uses the latest scientific knowledge in the field of motion therapy. Unlike other exercise equipment, Powerball uses no weights, springs, electrical power or batteries. Instead, it uses the power generated by a rapidly spinning gyro – gyro power.
How much, or how little gyro power, is controlled by the user’s muscle strength and is thus easily adjusted to suit the user’s physical condition. The gyro energy generated from 10,000 revolutions a minute amounts to around 15 kilos or 33 pounds !
How does the Powerball work?
The Powerball works without batteries! It is driven by pure muscle power. Inside the device, you’ll find a 200 gram rotor - the heart of the Powerball. Once it’s set into motion, a rotation impulse starts up around the axis. Bike riders are familiar with this kind of impulse. If you get on a bike that’s not moving, you’ll fall over. But the faster you ride, the more stable the bike becomes. As speed increases, more power is required to steer. The rotor within the Powerball is able to build up stability in exactly the same way – through the moment of inertia (the gyrating mass is about 2 cm (1/2 inch) from the axis) and the rotation speed. The user can now try to tilt the rotor, while simultaneously turning the rotation axis, to create a moment when the rotor begins turning. The gyroscope reacts to this movement with an opposite motion in an attempt to straighten upright again. This force is known as “precession”.
Powerball builds strength
This unique gyro exerciser helps build upper body strength, particularly grip, wrist, upper and lower arm strength, as well as sharpening co-ordination skills.
Source taken from https://www.nsdpowerball.com.au/
POWERBALL
What is Powerball?
The Powerball is an exercise device. Developed in the USA, it uses the latest scientific knowledge in the field of motion therapy. Unlike other exercise equipment, Powerball uses no weights, springs, electrical power or batteries. Instead, it uses the power generated by a rapidly spinning gyro – gyro power.
How much, or how little gyro power, is controlled by the user’s muscle strength and is thus easily adjusted to suit the user’s physical condition. The gyro energy generated from 10,000 revolutions a minute amounts to around 15 kilos or 33 pounds !
How does the Powerball work?
The Powerball works without batteries! It is driven by pure muscle power. Inside the device, you’ll find a 200 gram rotor - the heart of the Powerball. Once it’s set into motion, a rotation impulse starts up around the axis. Bike riders are familiar with this kind of impulse. If you get on a bike that’s not moving, you’ll fall over. But the faster you ride, the more stable the bike becomes. As speed increases, more power is required to steer. The rotor within the Powerball is able to build up stability in exactly the same way – through the moment of inertia (the gyrating mass is about 2 cm (1/2 inch) from the axis) and the rotation speed. The user can now try to tilt the rotor, while simultaneously turning the rotation axis, to create a moment when the rotor begins turning. The gyroscope reacts to this movement with an opposite motion in an attempt to straighten upright again. This force is known as “precession”.
Powerball builds strength
This unique gyro exerciser helps build upper body strength, particularly grip, wrist, upper and lower arm strength, as well as sharpening co-ordination skills.
Source taken from https://www.nsdpowerball.com.au/
