Good advice (as always) from Jennie on why templates are not necessarily interchangeable.
Acrylic rotary cutting templates are truely excellent in allowing us to cut multiple layers fast and accurately BUT while different manufacturers claim the rulers do the same job (and indeed they do) you need to pay attention as they are not necessarily interchangeable by that Jennie means that some patterns are very specific about the manufacturer.
Also, some rulers are marked in inches that you can use to count i.e. real measurements, and others are designed to do the maths for you i.e. what to cut in order to achieve – so again you need to know what you are using.