Review on 📏 Empire E250IM Heavy Duty Professional Combination Square: Stainless Steel Blade, Inch and Metric Graduations, True Blue Vial - 12-Inch by Carlos Deuschle

It looks well made. I used it happily for a project until I found a trivial way to test it for true "perpendicularity". I held it flush with the 2x8 page and drew a line. I then flipped it over (rotated 180 degrees), held it flush again, and drew another line over the first. The lines were noticeably tilted and deviated by 1/16" from 8", meaning this square is actually 90.4476 degrees, not 90.0. (I repeated the same test on the same board with a different speed square and the lines overlapped perfectly, so the board wasn't straight in the area I was testing.)