Set of massage balls in 3 different hardness's for acupressure massage and trigger point release. Starting with the softest (least aggressive) ball choose a ball of suitable hardness and position it on the point to be massaged. For the lower back or glutes start in a sitting position; for calfs or thighs try either sitting or lying on the floor and gently roll around on the ball. For shoulders; upper back place the ball between your back and a wall. For the neck roll the ball around between your neck and open palm. Use in conjunction with a foam roller for great results! Product details: Dimensions - 6cm diameter Hardness's - Grey - Hard/ Green - Medium/ Blue - Soft. Material - PVC