It can help to improve your performance in any activity quickly that requires grip strength and the use of your hands and wrists. Note: The hanging weight should not be more than 20 pounds. Usage: Stand, hold the roller with hand, exert yourself to roll up hanging objects, restore with controll. First frontal roll then back roll, repeatedly operate. Rugged steel construction, durable nylon rope, can be used with standard discus to develop training devices for training wrist and forearm strength size:39cm Material:Steel pipe + foam + nylon rope colour:black Package Contents: 1 * Wrist Roller Exerciser Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.