The knobs of the four legs of the Jacknobber II massage tool can be used in many ways to apply deep pressure to myofascial trigger points and areas of muscle tension. Equally comfortable in small or large hands. Even children enjoy its ergonomic shape! The smaller knobs provide more intense pressure while the larger knobs provide a more diffuse pressure. Use one knob at a time to press deeply into taut bands with embedded trigger points. Use two knobs at a time on either side of the spine. Use all three to gently sweep across broad muscles of the back, glutes, legs, shoulders and torso. Best used over lightweight clothing. Arguably this is the most satisfying and easy to use hand held massage tool available. Proudly made in the USA. Colors vary.