US Patent 7513055 Slope Level

A slope level for measuring the slope of a surface is provided. The slope level includes a body having a front face and a back face and defining a first planar measurement surface. A transparent arced tube is disposed in an opening in the body. An aperture in at least one side of the level frame can allow for viewing of an arced tube through a clear cover protecting the tube. The clear cover may comprise a plastic material positioned between the side of the frame and filler material inside the frame and defining the groove, with the portion of the clear cover at the aperture extending outward so that the clear cover is flush with the side of the frame.