The latest break-through technology to help build up hand, arm, shoulder, and especially wrist and forearm strength. Helps improve fitness and power in golf, tennis, bowling, basketball, and other sports. Helps improve hand coordination and circulation. Dual-Action Capability Adjustable Tension Bar High-Density Comfort-Foam Grip Custom-Fit Band/Arm Guide This Exerciser has got some goods reisitance with Tough Coiled Spring as resistance. If you participate in a sport that requires wrist and forearm strength and coordination, or weightlifting, you need a Power Wrist Strengthener