The MB2 Roller provides targeted relief to the neck and back to soothe pain, and improve flexibility and mobility. The adjustable length can be locked for use on smaller muscles that attach directly to the spine, or extended to target the larger muscles of the back. The massage balls use a patented, layered construction made up of different densities. The unique EVA foam compresses to "grip" the tissue, encouraging blood and oxygen flow to keep muscles and fascia healthy. The MB2 Roller is designed to be lightweight, compact, and durable for easy travel use and mobility on-the-go. Item dimensions: 9.5 x 4.3 x 2.6 inches; item weight: 0.24 pounds/109 grams.