xplosion -proof hand stubborn chains should be suspended vertically. There must be no wrong chain ring. The operator should drag the bracelet in the same plane as the bracelet, so that the bracelet can rotate along the clockwise direction in the clockwise direction of the bracelet, which can increase the heavy objects; dragging the bracelet in the reverse, and it can slowly decrease at noon. When having heavy objects, it is strictly forbidden to do any job or walk under heavy objects to avoid personal accidents.