Unfortunately these are faked a lot, and given the number of returns to Amazon, I would be surprised if some people substitute the counterfeits and return them to Amazon. Also Amazon is just a storefront for other online vendors, not too long ago I ordered some machine parts from Amazon and they ended up shipping from China arrives weeks later after the project needed to be done. The product pictures are often generic or substituted, and not what you will be getting. This is very common for the eBay China vendors selling Mitutoyo.
(1) The battery should read “SR44” and “Japan” on the battery itself (not just on the packaging), and there should be no battery already installed in the calipers.
(2) The calipers should come in a sealed plastic bag packed with a bit of Ferobrite anti-corrosion paper and a yellow tag on the locking knob telling how to install the battery and such.
(3) The display of these calipers should read, "0.0000" when zeroed out in the "inches" mode - counterfeits might read, "0.000" and might have a smaller 0/5 digit on the far right.
(4) The locking knob on the top should be the same shape and style as shown in the factory pictures, not as tall and a unknurled portion at the top. The fakes have a taller knob knurled from top to bottom
(5) The "ORIGIN" button should be recessed, also look at the difference in the plastic molding around the button.
(6) The batter covers are completely different, the original there is a straight mold line that continues across the cap, the fake the mold line swings down and around the bottom of the battery cap. The "ABSOLUTE" is printed on the original battery door, the fake it is on the body of the caliper.
(7) The serial number on the caliper needs to match the serial number listed on the calibration certificate.
(8) The calipers and packaging should not mention China - anywhere - especially not on the box/envelope/battery in which they were shipped.
(9) The fit and finish of the caliper, the copies have rough grind marks and often there will be a gap between the ID and OD jaws.
This is just a few things, there are numerous other differences, unfortunately many you need to have in your hands to tell.
Know what you are buying. I think getting an Absolute indicating caliper is worth the extra spend, the cheaper calipers that I use to use have had some measuring errors moving the slider back and forth, to the point I never trusted the reading, and would constantly re-zero and double check the readings. I have an Igaging Absolute 6" which I highly recommend, I have a real Mitutoyo 8" Absolute, and it is nice to work with and very accurate. I would suggest if you are going to pay the price for a "real" one, I would purchase it from a major tool vendor as opposed to save a few $ and be surprised.
