There is a very small part on the screw jack, called the supporting tooth. Although its position and shape are not easy to attract attention, it can save time and labor and improve work efficiency in the process of operation.

When in use, first rotate the rocker directly clockwise by hand to make the lifting sleeve quickly raise the top weight, insert the handle into the rocker hole, move the handle up and down, and the weight will rise accordingly. When a red warning line appears on the lifting sleeve, stop moving the handle immediately. If the supporting teeth are adjusted to the opposite direction when it is necessary to descend, the weight will begin to descend.