If you are investing in a vernier caliper, by all means buy a quality product such as this
genuine Swiss-made Brown & Sharpe vernier caliper shown here.
Brown & Sharpe Tri-Cal Model no. 599-577-1 (6" range)
Upper scale is metric (0,05 mm) and lower scale is imperial (.001"). The range is 6" or 150 mm. Stainless steel. Accuracy is ± .001" as with all calipers. Comes in a form-fitted hard plastic box and the manufacturer's certificate of calibration.
The lines and numbers on this caliper are lightly, but distinctly engraved into the metal. They are not printed on the surface like so many other calipers.
If you're a novice: once you get the hang of it, vernier calipers are easy as pie to read and there are no gears, dials or pinions to malfunction. They'll probably never need to be repaired. If you're unsure how to read the vernier, ask someone to show you. That's the best way to learn. To sum things up: we would rather have one vernier caliper than a dozen dial or digital calipers. These are the ones we use in our own shop and they haven't let us down in 57 years!
If you're a pro: no sales pitch needed.
Are the Swiss vernier calipers too expensive? Take a look at these Mitutoyo vernier calipers. Maybe they'll fit the bill.
Mitutoyo 530-312 vernier caliper with .001" and .02 mm scale with 6" (150 mm) travel
Do you need something larger? Brown & Sharpe only makes the 6-inch models, but Mitutoyo has the following vernier caliper option and at a remarkably lower price: (to make sure that you are not getting a Chinese imitation, make sure the item is sold by, and ships from Amazon or another authorized Mitutoyo dealer.)
Mitutoyo 531-112 Vernier Caliper, 0-12" Range