The Fitness Circle® Pro is a must-have for all Pilates instructors. Used on the Mat, the Reformer, or other equipment, this portable piece helps maintain proper alignment and increase proprioceptive awareness. The Fitness Circle® Pro is made of spring steel and built to withstand continuous, high-intensity studio use. Add resistance for upper and lower-body exercises—the Fitness Circle Pro improves muscle tone and is great for problem areas that are hard to firm up: inner and outer thighs, upper arms and chest. - See more at: http://www.merrithew.com/shop/ProductDetail/ST02099_Fitness-Circle-Pro-14inch-blue#sthash.IggH485f.dpuf