A few years ago I bought the Eurolite version of a 30cm half mirror ball. It was ok (review on Thomann).
This Showtec version is also ok. But it's a bit more ok than the Eurolite version and it's 10 Euro cheaper. I just bought 2 of these and I would choose the Showtec again over the Eurolite. I'm sure these two versions probably come from the same factory, but I do prefer the Showtec for more consistent quality (such as it is at this price level).
I bought the pair of Showtec's for a pair of "floor mounted" mirror balls. The motor in the Showtec is nice and strong. I couldn't stop it with reasonable hand force. Also the bracket arms are square to the mounting surface - this was one of my complaints about the Eurolite, they aren't.
The (half) ball is mounted to the motor spindle with a nyloc nut and a split pin. There is also an internal secondary bond wire.
About 0.75m of flex is provided. There is no plug fitted.
It's a synchronous ac motor so can start rotation in either direction. With hand force, I wasn't able to stall the motor and get it to rotate in the other direction, which is very useful for my floor application.
All mirror facets were intact and securely mounted (again not the case on my Eurolite). Because this is a small diameter ball, as you get towards the apex, there are a few gaps, because the mirrors are 1cm square.
RPM - not sure, maybe it's in the spec. From observation probably something like 30rpm; but whatever it is, it's about right.
Overall much happier with my 2 Showtec's versus the Eurolite I also have. So say yourself 10 Euros (pretty much a 25% discount) and buy the Showtec rather than the Eurolite (which strangely has higher Thomann sales). Hence awarding 5 stars since I gave the Eutolite 4.