and what Feel Flux teaches about Lenz's law

What happens when you drop the ball into the tube?






The movement of the falling ball creates a changing magnetic field inside the metal wall of the tube.


According to Faraday’s law of induction, the changing magnetic field induces a voltage called electromotive force inside the wall of the tube.


Because the tube is made of well-conducting metals, this voltage creates electric currents in the metal. These are called eddy currents.


According to the law of excitation, the flowing eddy-currents generate a second magnetic field that can affect the magnetic field of the ball.


Lenz’s law states that this additional magnetic field is always so directed as to oppose the motion that has generated it: the movement of the ball.


The faster the motion, the stronger the braking force gets. When the ball stands still, you feel no attraction at all. This dynamic behaviour of the effect is what makes Feel Flux so satisfying to play with.


Specs & Facts

The effect caused by Lenz’s law is hard to visualize: you need the very best materials to get an intense effect. With Feel Flux, you finally have the chance to get them.

Better electrical conductivity means slower ball

If the tube is made of a metal that conducts electricity better, then the same electromotive force can generate higher current. This leads to stronger magnetic reaction forces that slow down the ball more.

For the best performance, we use ultra-high purity copper for the Flux Original: it gets the most intense effect for those who seek to see and feel a mind-bending phenomenon.

Skill Flux is engineered to be fun overall.

The aluminium alloy is much lighter than copper but still a good conductor. The faster ball makes the tricks more challenging and engaging. 

Slower ball

More relaxing

Alpha state


Faster ball

Exciting tricks

Crazy combos

More thrilling

Flux Original




279 g (9.85 oz)

60 mm (2.36 in)

60 mm (2.36 in)

552 g (19.5 oz)

50 mm (1.97 in)

60 mm (2.36 in)

Skill Flux

Skill Set

Pro Model

The ball

Not only do we need great conductors in order to get an intense effect, but we also need an extremely powerful magnet. So we include the strongest type of permanent magnets humankind can produce. 

The stronger the magnet, the slower the ball gets.

Grade: N52

Material: Neodymium

Compound: NdFeB

Residual induction: Br = 1.48 T

Energy product: BHmax = 52 MGOe

Neodymium magnets are the most powerful magnets on Earth and Feel Flux includes the strongest grade among those. Here is how they stack up against other type of magnets:

Did you know?

The magnet ball can hold a weight of 15 kgs.


If you put it on a flat surface, it will turn itself to the north.


If you roll it on a wooden floor, it will find the nails under the boarding in the sleeper and stick to them.


It noticeably repels water.

A magnet so strong it bends water

Water is thought to be completely immune to magnetic fields, but in fact, it is very slightly diamagnetic, which means that magnetic fields repel water. This effect is 500 million times weaker than the attraction between magnets and iron, so the repulsion is mostly imperceptible. 

However, the magnet ball included in every Feel Flux package is so strong that even such a minimal effect can become visible. If the magnet ball is held close to a water surface, the powerful magnetic field pushes the surface below itself creating a clearly visible bend in the reflection.

Feel Flux

magnet ball

Water surface

reflecting a mesh