With two distinctive sizes for variable coverage, the TRNR Trigger Balls deliver a deep tissue massage that is tailored to different muscle needs. Showcasing a 4.5 and 6.5 cm diameter, the Trigger Balls are specifically designed to unlock trigger points, breaking up any soft tissue adhesions that may cause unwanted movement restrictions. Use them handheld or by rolling with your own body weight to target your forearms, deltoids, pecs, hips, glutes, and calves, or any specific areas in your back that are particularly hard to reach.