The TriggerPoint MB5 Massage Ball is a compact foam massage ball that can provide massage-like relief to hard-to-reach muscles like the glutes, hips, and shoulders. At 5 inches in diameter, the MB5 has the size to dig into those larger muscles, kneading out knots and loosening them up post-workout. Massaging those tight muscles helps to encourage circulation, speeding up recovery from injury. If you need to reach some parts of the body that you can't quite get to with a traditional foam roller, give the MB5 a try!