The unique, smooth resistance system builds the flexor and extensor muscles while enhancing your grip strength. The mechanism supports your forearm and wrist for maximum safety and comfort, while a variable resistance system allows you to measure your progress. The grip is also adjustable to suit a wide variety of hand and arm shapes. Designed specifically to strengthen wrist and forearm muscles. Made from durable poly resin with padded contact points and adjustable hand grip for a custom fit. The adjustable tension allows you to customize your workout.