These protractors tackle large jobs.Both styles include a black easy-grip locking knob, adjustable clear plastic magnifying pointer, non-corrosive hardware, easy to read numbers, a hang hole for storage, and a composite brake material for locking arms in place. The dual arm Equalizerª Protractors 18Ó& 36Ó lengths, are made of anodized aluminum for corrosion resistance and have hang holes. The 72Ó dual make of 1/4Ó tk aluminum. The 4Ó diameter dial is graduated to 1 degree, with 1/2 degree readings possible. Arms rotate 270 degrees. Various elements of industry find these protractors a much needed necessity to accurately measure/set-up angles, saving time and money in the process. Used by: Engineers, Welders/Fitters, Sheet Metal Fabricators, Tube and Pipe Fabricators, Wood Workers, Drafts Persons, Inspectors, etc. Related products;