These are an excellent deal. I work with a CNC machine all the time and we use these things all day long. Only problems I've had are the little screws falling out of the end support and the batteries don't last a long time. Sometimes comes on after it's turned off. Very accurate. Great for really long items or large ID items. On sale price is usually $40.

I have a blue version of the 12" digital caliper, picked it up for $20 on ultra-clearance, works great, has large display and seems to be very accurate when checked against a block.