NWT P.Volve Massage Ball Set A must-have set to use on your feet, calves, between the shoulder blades, and more! Provides pinpointed muscular and fascia release Helps improve flexibility Helps reduce soreness Use massage balls on larger muscle groups to start, then gradually move to smaller ones. Use your hands to roll over muscles in a circular motion. Stop when you find a sore area or point of tension and apply gentle pressure for about 30 seconds. Do not press massage balls into your joints or bones. Single ball: 0.35 lb..; 2.5 inches in diameter Double ball: 0.75 lb..; 2.5 inches x 5 inches