I have done my best to capture the degree of inaccuracy of these so-called corner details in the photo. If you look at the photo in comparison to the true reference square, you can see that the red unit touches at the far right end, but has a significant gap in the corner. This indicates the angle error of these aluminum blocks. This is a copy of a much more expensive and much more accurate known device of a similar design. This is definitely a case of "you don't get what you paid for" with these cheap fakes. The aluminum material and anodizing seem good, but without manual finishing they are really useless for their intended purpose. In case you're wondering, I've compared them to several squares, not just the brass you see in my photo. In all cases they got out. Luckily all the other squares in my workshop are way more accurate than this junk. I could take the time to manually adjust them with a file to get them right, or they could just end up in metal recycling.
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