TriggerPoint's line of hand-made foam massage balls is specifically designed to replicate the feeling of a massage therapist's hands, so you can get relief from discomfort and tightness on your own. As part of the Deep Tissue Essentials product line, these massage balls use a patented, layered construction made up of different densities. This design works to break up adhesions and stimulate blood flow better than non-layered tools to ease joint and muscle pain more effectively, and restore movement more quickly. The unique EVA foam surface is very dense, yet still compresses to "grip" the tissue, keeping muscles and fascia healthy. The MB1 (2.6-inch diameter) is ideal for isolated areas, providing targeted relief without pinching or irritating nerves The MBX (2.6 inch diameter) has an extra firm surface that offers a deeper level of massage for more intense relief. The MB5 (5-inch diameter) has a large surface area that provides the unique ability to release tight shoulders, hips and groin. All three massage balls are washable, lightweight and slip resistant. They are more hygienic than cloth and will not breakdown after repeated use. All are backed by a one-year manufacturer's warranty.