I couldn’t find a good 14mm in my tools. This is the size for my oil pan plug, and I just lose them over time.
I tried to use a light-duty cheapie one, but the metal got damaged.
The replacement was kind of expensive, but worth it!
The shape of the corners is weird. There’s a bit of metal cut out of it, so it won’t touch the corner of the bolt head.
This was a patented feature on Snap On tools. The patent has expired.
What’s good about this feature, is that it avoids putting force on the corner of the bolthead. Instead, it puts force on the flat surface, which is stronger.