To save ~100€ from someone.. it doesn't work.
the sleeve has indifferent appearance, somewhere I read they say it has power but it doesn't have,
if your arm is more bulky the sleeve finds in the "window" and stops and if you remove the "window" it makes a lot of noise
It doesn't make a big movement so it's just to polish the handle.
It's not waterproof or even water resistant.
The sleeve because it has hard plastics inside doesn't turn inside out for easy cleaning and drying.
That's it.
With the 100€ go for drinks you will have a better time