Hi,  I have two dial calipers that I don't use. They both are deadly accurate but have some quirks that I'll discuss.

The Helios caliper is really nice and clean. Its quirk is that I think I bent the spindle a hair when cleaning it. It works just fine though. If you hold it in the right light you can see two micro holes in the crystal. I couldn't see them in the Ebay pics until it took it out in the sunlight.  I tested it against a guitar sting that is 0.010 inches thick and it read exactly 0.010 inches. Got it on Ebay a while back for fun. Its really nice. $25.00.

The Mitutoyo caliper seems to be in almost perfect condition. I didn't clean this one so no problems there. I got it at a guild estate sale. When I bought it a few years ago the manual was saturated with oil. I leave it in the case as it was sold to me. The quirk with this caliper is that the tail/probe used to measure the depth of a hole isn't flush with the end of  the caliper. So you have to zero it our when making a depth measurement or subtract the offset. This caliper is also deadly accurate measuring my instrument strings exactly 0.010 inches. $55.00

I hardly use these so I'm happy to sell them to someone who will use them. They seem equivalent in terms of accuracy. High quality stainless steel.  New ones run $110 and up if made in Japan.

If you don't have a caliper, they are worth checking out.

Mark