This heavy duty mobile machine base with its two fixed and two castoring wheels is a convenient way to enable heavier machines or work stations to be moved around the workshop. Once the machine is positioned, the castoring front wheels can be raised with the screw-in feet to allow the base to rest securely on the floor. Maximum total load is 450kg and the size limits are 570mm square up to 750mm square or 570 x 750mm up to 870 x 750mm rectangular. Very well made and easy to use.