"The GoFit UltraFin Core Massage Roller is engineered to allow deeper pressure with greater stability for muscle massage and stretching. This unique inner support structure, along with our already-effective foam patterns break down and release the body's ailments and stresses. Unlike other traditional ""hollow"" foam rollers, the UltraFin Core withstands the most intense therapy sessions in the industry, helping your body to improve blood circulation throughout your skin, fascia, muscles and even tendons and ligaments. Patent Pending Gender: unisex. Age Group: adult."