Way back in 2009, Lego released a set called "Designers' Tool Set" which had a brick separator and a rather cool triangle ruler. They unfortunately don't make this anymore and getting hold of one now on the second hand market will set you back £30 or more even if you can find one. 

This listing is for a custom made 3D printed Red Triangle Ruler / Human Sorting Tool similar to that Lego part and is NOT official Lego. The original part number is bb0342 from set number 852690. 

This ruler has markings for brick height, stud count, lengths of Technic lift arms, and lengths of Technic axles. It also has a hole for hanging the ruler up.

Comes unfinished or with black numbers.   

Please see photos for more details.  

 **LISTING IS FOR THE 3D PRINTED RULER ONLY, LEGO NOT INCLUDED**  

Enjoy! :)