I have two TriggerPoint GRID foam rollers (one at work, one at home) that I love and use regularly. Sadly, this ball does not make the cut and I would recommend the much more effective (albeit more expensive) MobilityWOD SuperNova for this type of self massage.
The ball is way too soft to conduct self myofacial release and after my first session with it the ball turned into an orange oval. It does not seem to have the dense core that would add the structure or rigidity to support body weight and transfer the amount of pressure needed for rolling out like their foam rollers do.
While the price point is attractive, you're better off investing the extra $20 and getting something that's actually going to be effective.
The TriggerPoint Grid Ball combines the best of both worlds, blending a next-generation massage ball with TriggerPoint's innovative Grid pattern foam rolling technology. With a compact, lightweight and portable size, the massage ball design makes for an efficient tool for targeted pain relief. The Grid Ball's 5-inch diameter elevates the body to better target hard to reach areas such as the hips and shoulders, while the signature Grid pattern channels blood and oxygen to repair muscles as you roll. The Grid Ball is a convenient recovery aid for use almost anywhere, at any time to help release muscle tightness and improve flexibility in anyone experiencing muscle pain or tightness. The TriggerPoint grid ball is approximately 5 inches x 5.7 inches x 6.4 inches; 325-pound weight limit; 1-year manufacturer's warranty.