Have appointed recently 9 of this sleeping cube, although the manufacturer directly, but nevertheless I would like to say a few words about it. I have the dice brought only for colleagues at work as a gag, but if you used this time during the break you can really his inner Charging something. It can be real relaxing for a few minutes just once to make the eyes and to doze;) The cubes are made of durable sponge but they do not scratch and are comfortable to wear on the chin. Depending on how long the neck, you can rotate the cube and has a different length. The price is maybe a little high but it does not make me poor, as had and still have a lot of fun to use this cube;)