The spiral jack is also called manual jack, mechanical jack, and hand -shaking lift. Using a relatively small force to rise and move heavy objects, it can also be used to correct the device. Pay attention to some points when using: 1. Wipe before use, and check whether the lifting screw, piston and other action components are flexible and whether it is damaged. 2. When using it, it should be placed on a flat and hard ground. If there is a loosening, the padding plate and the pillow wood are expanded to expand the area to ensure cleaning to prevent slipping. 3. When operating, roll up a little, and see if the ground is firm. 4. Slowly decrease when landing to avoid damage. 5. Do not use the accident that causes accidents. 6. Multiple units at the same time are promoted at the same time, and special persons must be conducted to achieve consistent actions to ensure that heavy objects are stable and safe.