The Exquisite Design Surface Adopts Special Anti-Collision Design, Which Is Firm but Flexible, Just like the Massager's Fingers When You Use the Roller, the Bulge on the Roller Will Continue to Massage Your Body and Gently Stretch Your Soft Tissue (Muscles and Fascia) in More than One Directions. The Trigger Point of the Muscle Soreness Solution Helps Restore Flexibility and Quickly Relieve Common Muscle Pain. Carefully Developed in Design, the Bulge Is More Solid than Muscle Tissue, but Softer than Bone, therefore, the Two Versions (Original and Ultra-Tight Versions) That Will Automatically Turn When They Touch the Spine Or Other Bones Have Been Automatically Turned by Independent Laboratories According to the Consumer Goods Safety Improvement Method (CPSIA) of 2008. The Test Standard Tests Lead and Phthalates. Both Toxic Substances Are below the Detectable Level and Meet the Use Standard of Cpsia12 Years Old and below. All Products Do Not Contain Latex.