Sahara Sailor Finger Exerciser Hand Strengthener Adjustable Handmaster Hand Grip Hand Exerciser 1. Challenges each finger individually using patented spring-loaded finger piston technology, Each one of the five pistons can be independently manipulated or locked into place to meet anyone's needs or specifications; 2. Improves user control of bats, racquets, clubs, guitars, and other sports equipment; 3. Heavy tension strength of 9 pounds per finger for strong hands; 4. Develops and maintains the strength and dexterity of your fingers, hands and forearms; 5. 365-DAYS MONEY BACK GUARANTEE - if our hand grip strengthener cannot meet your 100% satisfaction, please do not hate to contact with us for fully refund