Silicon Massage Lacrosse Ball. with It, You Can Custom Trigger Point Massage at Home to Exercise Your Full Body Muscle, Eliminates Muscle Knots & Tension, to Rejuvenate & Revitalize All Areas of the Body. Simply Lean on the Massage Ball & Use Your Own Body Weight & Gravity to Relieve Muscle Knots & Tension. Perfect for Use While Sitting on Any Chair, Laying in Bed, on the Floor, or on a Yoga Mat. Use Them at Home, at the Office, or at the Gym. Small, Portable & Easy to Bring Along on Any Trip. Official Size & Weight Makes It Great for Lacrosse Practice.2.5inchs.