The wrist roller is designed to help you improve your grip and create stronger, leaner muscles through progressive board training that suits your strength and fitness level. grip diameter: 3.5 cm. Material polyester cotton webbing, double-layer airtight sewing technology, length 1m / 39.3inch. Bearing capacity: within 200kg / 440lbs. carbon steel body. Plastic spraying frosted particles + knurled surface. Polyester-cotton webbing, double-layer airtight sewing technology. The webbing line is firmly connected to the weight plate bracket and handle, suitable for all fitness and skill levels, and is an ideal tool for all sports training. The fixed rod is installed on a stable desktop, and the rotating rod is sleeved on the fixed rod. After the rotating rod and the fixed rod are installed together, a dumbbell of a certain weight is hung on the lower end of the webbing. Hold the handle and rotate it clockwise or counterclockwise. Wrist and forearm shock waves help strengthen the wrist, arm and forearm, and increase muscle tension. It is an excellent training tool for weightlifting, golf, baseball, tennis, rock climbing, surfing and other fitness sports that require wrist and forearm strength.