Abstract: A spirit level having a measuring stick slidably mounted on one end of the level with means attached to the level for clamping and releasing the free transverse movement of said measuring stick from a position near the center of the level. A separate bracket is provided for attachment to the level for the clamping means which bracket also may include guide means for the measuring stick. The clamping means comprises a spring urged frictional brake which engages the measuring stick and is releasable by a thumb operated handle slidably mounted adjacent the vial which indicates when the level is level. This guiding bracket may be longitudinally extended with respect to the level to increase the length thereof.