Product manual: Material: High-Quality Environmental Protection Abs And Steel Pipe Function: Relieve Tension Effectively Reduce Fatigue And Soreness Caused By Exercise And Mental Tension.  How To Use :Put The Massage Stick On The Thigh And Roll Back And Forth To Effectively Relax The Thigh Muscles And Bid Farewell To The Stiff Muscle Legs. Put The Massage Stick On The Neck And Roll Back And Forth To Relieve Neck Muscle Tension And Say Goodbye To Shoulder And Neck Pain.