Brainstring Original is a patented brilliant puzzle for people between 7 and 70. Brainstring Original comprises a transparant polycarbonate cube with 12 elastic strings. Using an ingenious pattern of incisions the strings can be moved through the cube. The result: complex knots appear on the inside. The main goal of the game is to switch the outside button colors, without creating a knot inside. It seems impossible but…

Back in 1992 inventor Guido Lap came up with the idea of interchangeable strings. Ten years later Brainstring Original was introduced and almost immediately became a worldwide bestseller!

Features:
Dimensions: 8cm x 8cm
Made from transparent polycarbonate
24 buttons, 12 elastic strings

Review from parent24.com

We like
It may look like an innocent puzzle toy, but the Brainstring has all the tormenting qualities of a Rubik's cube with a bad attitude. My teenage son tried for 15 minutes, then threw it across the room in defeat – so at least its construction is sturdy!

The younger kids in the house played with it much longer, and even Mom had a go, although I was probably more defeated by it than anyone. Being able to see the string inside makes you feel like the solution is closer than it really is. Sneaky! It's quite addictive – every time you think you've given up, your hands reach out for one last try.

We didn't like
It's pretty hard, so it's only for those who enjoy brainteasers.