PEC is among the best of the best in measuring tool manufacturing, and has manufactured precision products in the USA for top brands like Mitutoyo, Brown & Sharpe, and Lee Valley. The fully hardened and tempered 4” blade has an easy-to-read satin chrome finish with E/M graduations (both imperial and metric—mm, .5mm, 32nds, 64ths). Jonathan’s Hot Take: A good square is the most important tool in your shop, and the FIRST high quality tool you should buy. I’ve carried PEC squares for years. The PEC double square has extreme tolerances (within .0015"), ensuring precision and accuracy. And the graduations are photo-etched, giving it a tactile feel and making it easy to set a marking gauge, dividers, or knife line. I use my double square for all kinds of tasks, like laying out joinery, checking for waste in dovetails and mortises, and setting the blade on my table saw. To top it off, PEC is in our own backyard, just 2 hours away from KM Tools headquarters.