PURPOSE: To stabilize apedestal or goods or the like which are designed to be movable with the pedestal in a level state even if there is a slight deformation in the pedestal itself or on a plate or if a machine frame is installed with an inclining angle.

CONSTITUTION: While an intermediate ring body 20 is designed to be screwed into an inner ring body 10 and the tip (not shown on the drawing) of a screwdriver to be inserted into a corner 10b of the inner ring body 10, it is also designed to make the inner ring body 10 movable in either upper or lower direction when the inner ring body 10 makes a rotatable operation by the screwdriver. With the inner ring body 10 and the intermediate ring body 20 combined together as described and mounted on an outer ring body 30 and as the curved surface portion of the intermediate ring body 20 makes a smooth sliding, it is moved to a desired position.