Of course, the Shtox glass is not a perpetuum mobile, and it spins not because of some unknown supernatural powers. It spins because of the movement of your hand. But still... all the same – why does it rotate, unlike all other glasses??? The secret lies in a unique, specially designed shape of the bottom of the Shtox glass. During the production of glasses at the factory an experienced grinder manually brings up the form of the bottom of each glass to the right one. Such high precision of grinding allows the Shtox glass to spin and at the same time, not to sway from side to side.