Abstract: Two extruded aluminum or plastic channel members facing each other and with one confined within the other provide a plumb-rule of basic length and extendable to nearly double that length. The outer channel contains longitudinally spaced spirit level bubbles, a protractor level, and a bulls-eye level bubble all viewable from the exterior through corresponding openings in the back and side walls of the channel, and located free of interference from the inner channel. A counter is incorporated near the upper end of the outer channel and actuated by the extension movement of the inner channel to indicate the extension in increments of distance.

Abstract: A stand off for masonry or carpentry levels is disclosed which includes a substantially U-shaped portion having a clear-drilled boring through which a spring-tensioned cylindrical body extends having fastened at one end a disc-shaped end section enclosed within the U-shaped portion and at its opposite end, a disc-shaped pad for touching engagement with objects whose level is to be measured.