58 
15 Your machinists' ruler is a bit hard to read at a glance
The ruler you sell in your store is pretty useful, but has one big problem (for non-americans). The mm scale doesn't highlight 5mm increments, like pretty much all other metric scales do, as such it makes it pretty hard to read at a glance.
A normal metric machinists' ruler
vs. your machinists' ruler
Is this a good question?
Score
6
6