In case you haven't seen it, there are no AC measurements other than I put two of them side by side and the difference between them is 20 millivolts, indicating 12 volts. You get what you paid for, but it's good enough for general use.
Kapro - 353 Professional Ledge-It Try & Mitre Square - For Leveling And Measuring - Features Stainless Steel Blade, Retractable Ledge, And Etched Ruler Markings - 12 Inch
23 Review
π² Johnson RAS-1B Johnny Square: Professional Aluminum Rafter Square, 7'', Silver - Top Quality with 1 Square
8 Review
π Johnson Level and Tool 400EM-S 12-Inch Heavy Duty Metal Combination Square for Professionals, with Inch/Metric Measurements, Silver - 1 Square
8 Review
Kapro 307-08-TMS Try And Mitre Layout And Marking Square With Stainless Steel Blade, 8-Inch Length
18 Review