Furniture Design Quadro Qusabi Shelving System by Sonia Ponka Quadro Qusabi Shelving System (or shortly QQ) has been inspired by versatility of scaffolding. Qusabi (means "wedge" in Japanese) are inserted in posts openings at desirable height. Shelves and drawers are placed on Qusabi wedges without tools or nuts. Any shelf or a drawer can be replaced at any time. It is easy to assemble a new QQ system only with 2 shelves, 4 posts and one stopper. The smallest shelf`s size is 280 square cm. Other shelves`sizes are 8 cm wider or longer. QQ system can be reassembled as well as expanded endlessly by adding new posts and shelves to existing system.