Description 3 Spiky Massage Balls for massage, relaxation exercises, hand therapy & reflexology. When to them Apply in circular motions for a firm massage & to improve circulation. Stimulate muscle reflexes to ease tension & provide relaxation of the body. Size 6cm (orange) 8cm (yellow) 10cm (blue) How they work Use for a self massage or with assistance to treat back pain, improve circulation, stimulate muscles & ease tension. Individual sizes are specifically designed to target different areas of the body. The large 10cm blue is for use on the back, the 8cm yellow for the arms & lower legs & the 6cm orange for massaging the hands & feet. Can be purchased individually or as part of a set for instant massage therapy.