Ultra-high-strength engineering plastics and super firm anti-corrosion plating spring, which guarantee a longer life of this forearm developer. Thicken the sponge so you won& 39;t get hurt during training. Finger shape design, more suitable for grasping this exerciser. Beautiful appearance, moderate size, easy to carry, and can be adjusted at any time. Features - Color: Black - Material: Rigid plastic - Size: 22.5 x 14cm - Ultra-high-strength engineering plastics and super firm anti-corrosion plating spring, which guarantee a longer life of this forearm developer. - Thicken the sponge so you won& 39;t get hurt during training. - Finger shape design, more suitable for grasping this exerciser. - Beautiful appearance, moderate size, easy to carry, and can be adjusted at any time. Strengthen your forearm and wrist force anywhere.