Aroma hand exeriser 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 l ight to heavy, providing all-in-one hand fitness for musicians. How to adjust finger tension: AHF-03 individual finger tension is adjustable. The tension ranges from 4Lb to 7Lb. It’ s faul t set t ing 4Lb. If you want to increase the tension, please roll each finger as directed by the arrow printed on the exerciser, t i l l a sound gendered, i t reaches the most tension-7Lb. I f you want to decrease the tension, please loose each finger till being unable to loose the finger, it’ s the least tension-4Lb How to exercise: Start 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. Specification: Brand:Aroma Model:AHF-03 Tension range: 4 Lb-7 Lb Dimension:87mm×68mm×23mm Weight:74g