The Tiger Ball 5.0 is a lightweight foam roller ball, great for travel, and perfect for bigger muscle groups, such as hips, glutes, back, and shoulders. Ball massage surface provides targeted muscle care and relief of minor muscle aches and soreness. Use your weight as leverage and let the tool do the work. Use on the floor, chair, bed or wall. 5.0" massage surface. The ball won?t change shape despite the pressure or body weight. Check out our book "Happy Muscles" to help identify muscle knots/trigger points our tools can help with.