The Jackson Safety Contour Dial-Set-Level is an adjustable bubble protractor used with a number of the popular Jackson Safety Curv-O-Mark tools, including #4, #6, #7, #8, #20 and #33 (all sold separately). The protractor covers 180 degrees through two 90 degree quadrants, reading in 2.5 degree increments. The bubble is cast in the aluminum dial for durability. Contour and Curv-o-mark layout tool and systems have earned a reputation for quality and consistency across a wide range of industries. Easy to use and made for a substantial working life, these are tools to help bring precision to any layout task.