Ultra Sport Hand Exerciser: Hand Gripper 11 lbs to 44 lbs (5-20Kg) Europe's best selling hand strengthener; the gold standard for building and testing grip strength. Get the quickest gains in grip strength and hand health. Built for high repetition endurance training. Features three interchangeable weight resistant caps for total training flexibility. Features molded thermomplastic handles and aerospace cushioning inserts molded into handles for added comfort.