As I have posted in the past I use all the Woodpeck rules and have just about every single item they sell for measuring. they all read the same from instrument to instrument which is actually quite unbelievable as I do not think I have two tapes that give the same measurement.
Anyway, here are pictures of two items that are not as common as rules, T-squares and squares, etc. The Rotape for drawing circles is indispensable and the circle guides for transferring and enlarging existing shapes and for scribing I use often.
The circle guides are really nice if you have corresponding router bits that match the guide sizes. It is simple to trace a new shape for a template where you want to use the same template for both positive and negative image when using these circle guides.
Nickao