There are Vernier calipers with imperial and metric graduations. Our 3D model is with metric graduations, and if you need imperial graduations, you will have to draw it yourself, which is not so difficult if you know the basic functions of FreeCAD software. The 3D model consists of bodies that form a non-constrained assembly and it was drawn using the Part Design workbench; the metric scale was drawn using the Lattice 2 workbench and the Shape string command from the Part workbench. In order to be able to use this 3D model (e.g., for making illustrations), the assembly is divided into Main Body and Sliding Assembly subassemblies, so you can place the Vernier caliper on any dimension. The name of our site is also written on the 3D model – you are free to either delete it or leave it (in case you want to thank us for getting it for free).
If you need instructions on how to use the Vernier caliper, you can find it on the page Vernier calipers.