... grade led Item No.: 868NC Product name:Wrist ball with LED and COUNTER Description:Shell material: A grade PCRoller material: ... strength in fingers, wrists,hands,forearms,biceps,triceps,ligament and shoulders.-Great benefit for musicians,guitarists, pianists,drummers.-Rehabilitates ... will burn.-Do not use this product persons who with heart conditions of any description.-It is recommended strongly ...