1. Finger grip strength: Hand trainer equipped with carbon steel springs that provide a tension of up to 45 kg / 99 lbs. The Finger Grip Strengtheners of springs are smooth, lubricated and provide an effortless rebound for an even, pinch workout. 2. Unique design: Five independent buttons with ergonomic distances allow precise training of the fingers and palms. Strengthens the flexibility, endurance and grip of each finger, improving the overall performance of the hand 3. Massage palms: Our grip strength trainer has many precisely designed hexagonal grooves on its surface. With close with the palm, it can stimulate the acupuncture points of the palm, activate blood circulation and eliminate blood congestion, promote blood circulation, relieve fatigue of the palm and body and improve fitness effects. At the same time, it is promoting and has obvious longterm effects. 4. and lightweight: It is easy to carry. Use it at home, at work or on the go to relieve stress and strengthen the hand