This building element is basically operating as the LEGO-principle; any PAREIN plastic (ASB) building element can snap into a second identical element to form a brick with two raised disks. Then without any mortar or whatever, you can go and build, halfway superimposed on each other. In any direction as the extremities of the 'bricks' are round! Being a building brick, only temporarily serving as a closure or cup, PAREIN returns to its initial destination; assembling (by color) to something useful, even gathering towards recycling! The GREEN CAP bringing you all the colors of the rainbow!