3 million pieces sold in Europe. This is a 3D maze game that has sold over 3 million pieces in 16 months in Europe. It consists of a ring with a pronged stick and a maze engraved, spinning or pressing the ring to solve the mazes hidden inside the ring. When the ring comes off the stick, it's a maze attack. (6 Types of Difficulty Levels) 6 types are planned for sale from the easiest easy yellow to the most challenging terrible black. Now there are three colors to the silly green. But don't let the Easy Yellow stand up, this is a humanity to give up. Compact and convenient to carry. Keeps you bored while traveling in cars, trains, bullet trains, airplanes, etc. Groove tube is compact, so it is recommended for going out. Of course, no batteries required. Suitable for a wide range of ages. Not only can it be used by adults, but it is simple and simple, so children can challenge them. You will feel the pleasure and addictive.

(From Amazon.co.jp)