Developed in partnership with professional potter, Jennifer Whilden, the Speedball Boss Ribs allows for the ultimate ergonomic experience while delivering ease to the clay centering experience. Assisting with one of the most challenging aspects of the wheel throwing process,Boss Ribs provide additional support to aspiring potters to learn the centering process, minimize wear and tear on joints for seasoned potters and allow artists with sensory or mobility restrictions an opportunity to return to the wheel. Available in four vibrant colors (Black, Blue, Pink, Green); (1) 4in x3.5in rib, (2) 4in x 2.75in ribs, (1) 4in x 1.25 rib, (2) 1in x 12in strap