Open back pretty waist, plastic body, fascia massage small size, large, auxiliary yoga postures, wake up muscle energy is made of high quality PP material, environmental protection, non-toxic odorless a integrated ergonomic double arc arch design, strong bearing deformation, high-strength compressive strength, long service life perfect waist, neck joint human body physiological curvature, alleviate fully relax neck and shoulder, lumbar muscles. Compact and light, easy to carry, not subject to site restrictions, open practice at any time different models, prices are different!! Please consult before purchase!!