Gecko Blocks are a brand new construction toy technology! Utilizing the natural clinginess of silicon, these light foam blocks stick together (or to windows or bath tubs or anything smooth) like magic. The blocks never lose their stickiness because the stickiness comes from friction rather than chemical adhesion. If the blocks ever get dirty, simply run them under a tap or throw them in with bath time and the blocks come out as good as new. Gecko Blocks are Non-Toxic, waterproof, bath tub safe, and are the FIRST of their kind.