For over 20 years I have referred to this little pocket guide for the electrical field.
When I was first starting out it helped prompt with reminders of formulas and the like, as well as shrink and take-ups for pipe bending. It’s a great reference to have in your toolbox when you don’t have a full size codebook with you!
I give these to my new helpers when they start work and make sure they have an updated one as the code changes. It also serves as a great refresher because I’m not out in the field everyday and helps me remember so I prove I can still do it in the field (not just the office).
Ugly’s provides useful charts and quick reminders for the working electrical engineer.