321 STRONG Foam Roller Deep Tissue Muscle Massage Blue 13 Inch Hollow Core 321 STRONG foam roller features a multi-density exterior constructed over a rigid, hollow core for durable support during deep tissue massage. Designed with a textured surface including various raised zones, it effectively targets muscle knots and aids in myofascial release. The lightweight, portable design makes it suitable for post-workout recovery, physical therapy, or daily stretching routines. Measurements: • Length: 13" • Diameter: 5.5"