Many people may have or have bought vernier calipers for £10 ish, excellent value, measure in inches and cm and fractions of an inch, unfortunately magnetic, but for the price excellent value. But, they run through the little button cells batteries quite quickly. The reason is they are on all the time, it's just the display that the on/off button operates, so after use remove the battery. PS. Under a little tab usually at the top above where the batter is found is a connector for a digital output which is a handy hack.