White nylon plastic with a matte finish and slight grainy feel.
This is a puzzle of my own design. It has nine tiles, numbered from one to nine. A tile can move by swapping it with one of its neighbours. Not all tiles can be swapped though. A pair of tiles can only be swapped when their sum is divisible by three or five.
The main challenge is to restore the puzzle in its original position, with the tiles in ascending order. More challenges of varying difficulty exist. Thirty-six are described in a separate booklet.
It is a fun puzzle. Each tile has its own movement constraints. Some are easier to move around than others. There are also no general recipes for changing the position of two or more tiles. You need to analyse and plan ahead to solve the puzzle. Mindless trial and error will not get you far.