The 321 STRONG Foam Roller is a medium density deep tissue massager designed for home, semi-commercial, and commercial use. It is suitable for various muscle groups including chest, arms, back, biceps, abdominal, and full body. The foam roller is multicolored and can be used both indoors and outdoors. It measures 13 inches in length, and 5.5 inches in width. The foam roller features a hard massage grid and is made of foam material.