"Variable resistance training for hands, fingers and forearms. Helps strengthen grip, increase dexterity and improve finger strength. Four colour-coded levels of resistance provide a full range of exercise applications. Can be used for hot or cold therapy. Includes an illustrated exercise manual. Standard size has a 1 "" (4.4cm) diameter. New Large oblong exercisers measure 2"" x 2 "" (5.1 x 6.4cm) diameter and are ideal for larger hands."