What is SLZG?
SLZG is an abbreviation of SALZIG.

What is SALZIG?
SALZIG.berlin is an art/lifestyle brand and the creators of the sporthocker.

What is a sporthocker?
The sporthocker is a novel skill toy. It's the only one that is the combination of a sports device and a piece of furniture.
They are made from polyethylene plastic and are extremely durable and lightweight.

TLDR - It's a sport stool.

What is freestyle sitting?
Freestyle sitting is a result of a phenomenon that originated in northern Germany in the early 2000s.
People from the city of Kiel started trying moves and tricks with stools designed from the '70s known as Tem Tems.
This was known in German as 'Hockern' (stooling) and there were parties/competitions held for it.
Naturally, the stools they used had limitations and would break easily. Two German brothers fixed this by creating the sporthocker.

TLDR - Doing moves and tricks with a sporthocker.