The Trigger Point GRID X Ball is an extra-firm 5-inch massage ball to help target muscles in hard to reach areas such as shoulders, traps, and hips. Providing a deep tissue massage, the GRID X Ball has a firmer surface than the original GRID Ball to withstand more pressure and help relieve sore muscles. Foam rolling can help to aid in faster recovery by increasing the The GRID X Ball is an extra-firm 5-inch massage ball to help target muscles in hard to reach Extra-firm, 5-inch massage ball designed to provide targeted deep tissue massage in hard to reach places such as shoulders, traps, and hips GRID pattern replicates the feeling of a massage therapist’s hands to vary the pressure applied to the muscles Can aid in faster muscle recovery by increasing the blood and oxygen flow to muscles Easy-to-clean, lightweight and portable makes the GRID X Ball perfect for travel or bringing to the gym Extra-firm massage ball is 5 inches in diameter