Pluto hand exerciser AHF-03 is the ultimate all-in-one hand, wrist, and forearm fitness tool. Safely and conveniently build strength, endurance, flexibility and coordination. Our exclusive design features comfortable finger pads and allows you to adjust individual finger tension – from light to heavy, providing all-in-one hand fitness for musicians.SPECIFICATIONS:Tension range: 4 b – 7 b Dimension: 87mm x 68mm x 23mm HOW TO EXERCISE: Begin all exercises slowly and low resistance & few repetitions. Hold each position 3-5 seconds and relax-repeat 5 to 10 times. Little by little increase to 3 sets of 10. When graduating to a higher resistance begin again with 5 to 10 reps and build slowly. If you experience pain or fatigue-stop immediately. As with any exercise, escessive or incorrect use can lead to pain or injury. Therefore progress slowly and increase reps and resistance very cautiously.