Material: Material: made of chrome plated carbon steel spring, strong and durable, not easy to break, steel spring, grip strength exercise. Features:Stainless steel design will provide years of use and superior corrosion resistance. Well Designed Spring Resistance for Optimal Grip Strength Training for Golf, Fencing, Rock Climbing. Reasonable design: Stainless Steel Ergonomic Non-slip Grip | Built with Stylish Durability and Clinical Functionality - Physical Therapy, Arthritis Rehabilitation, Carpal Tunnel, Anxiety, Stress Relief. Size: (approx.) length: 9 cm/3.54 in, waist diameter: 5 cm/1.97 in, minimum diameter: 2 cm/0.79 in Packing list:1* Spring Grip Strengthener &1*Storage bag. FEATURES AND SPECIFICATIONS Simple & Sleek: Stainless steel design will provide years of use and superior corrosion resistance. Perfect for Athletes & Musicians: Increased grip strength and mobility will improve power, accuracy and finger speed. Portable & Lightweight: Small enough to fit into your gym bag or handbag. You can get repetitions in while commuting, at the office, at the movies just about anywhere. Functions: relieve fatigue, relax muscles, enhance finger flexibility and exercise hand strength. Suitable crowd: white collar grip strength promotion, leisure play for the elderly, leisure sports in parks, grip strength exercise for middle school students before physical examination, venting play after work, etc. Size: (approx.) length: 9 cm/3.54 in, waist diameter: 5 cm/1.97 in, minimum diameter: 2 cm/0.79 in Packing list :1* Spring Grip Strengthener &1*torage bag Weight: 168g