Adjustable universal builders spirit level - has two arms at right-angles with butterfly screw clamp

摘要

The adjustable spirit-level for use in building construction work consist of two standard bubble spirit-levels mounted at right-angles to each other. The longer of the two passes through a slot in one end of the second shorter level so that the latter can slide the length of the arm of the first. The shorter component is fitted with a clamping arrangement adjusted by means of a butterfly nut on its outer end so that the two parts of the adjustable level are firmly held together when the desired position has been selected.