I "discovered" PEC tools of California and was so impressed I bought some of their stuff to put it to the test of daily use. I am still impressed and I now recommend PEC's premium line of layout tools. Their protractor is very nice and really easy to read. I use this when I need to determine or set an exact angle. Measuring the angle of a primary bevel I am grinding on my plane iron for example.
I was very impressed, it is is very accurate.