The TRIGGERPOINT MB2 Green/Black/White Roller (3312) 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.Massage Balls details:Use two unique settings to target key areas of neck and backStimulate circulation and blood flow to improve mobility of the spineRelieve discomfort from back painFoam surface makes cleaning easyCompact, lightweight size for easy travel and portabilityGreen/Black/White Color