A hollow 3x3x3 cube, which can be played with and twisted like a normal 3x3x3. In the solved state the layer with the white/silver face can be removed from the puzzle. Then you have access to the inner hole. Originally offered for Jade Club members, Mèffert's included a small USB memory stick with a PDF-Document on it containing some historical information about the Pyraminx.
The puzzle mechanism itself was invented by Oskar van Deventer.
Size: edge lenght 6cm, height with tiles 6.2cm