Dijite Digital Caliper, Digital Caliper 6 Inch /150mm, IP54 Waterproof Caliper Measuring Tool Stainless Steel, 0.0005"/0.01mm Resolution, Large Auto-off LCD Screen, Inch to Metric Conversion

This particular calipers, unlike all the others I have bought, uses the commonly available CR2032 which is 3 volts and 220 milliamp-hours. This is a lithium coin cell with long shelf life and is used on computer motherboards to preserve the BIOS start system and real time clock. It may last 5 years. Lithium chemistry gives a nearly constant voltage until depletion, and the 3 volts is well above the minimum voltage that the display and circuitry need. The LR44 cell used in other digital calipers is 1.5 volts new, falling linearly to 1.0 volts with a capacity of 190 milliamp-hours. The circuitry won't work at 1.0 volts, and much of the battery power cannot be used before you can no longer use the calipers. The SR44 silver cell starts at 1.55 volts, but in my experience has a poor shelf life and has been no better than the LR44 in calipers. Its end of life voltage is 1.2 volts, so it should be better, but my silver oxide SR44 cells seemed to die as quickly as the LR44. The CR2032 at 3 volts is well above minimum needed voltage and has excellent shelf life.Other features of this digital caliper is nicely ground jaws, a good finish, and sealed for water protection to IP54.Disadvantages: The IP54 sealed battery compartment cover is hard to remove, and may require a tiny screwdriver to pry open. I could open it the first time with my fingers, but the second time required the screwdriver. Perhaps I closed it too tightly. In any event, the original battery already in the unit should last years. The circuitry needs only microampers, but does require 1.3 volts or more, so this unit was designed with the right type of coin cell.The picture shows a CR2032 on the left and the less desirable SR44 on the right. Note the large battery cover for the CR2032.

Update: I got a replacement set and they're dead-on, as tested on a set of feeler gauges. (My first set was a lemon.)Original review:ProsFit and finish are good for the price. No sharp edges, good machining, solid calipers. Accurate above 3/4". Good customer support via email.Cons:Small measurements are very far off. Between zero and about a 0.75 inch the calipers read low, but higher than that, it gets more accurate. Unfortunately, all the measurements I need to take are small ones (usually, between 0.008 and 0.100) and these are not useful for that. When I measure guitar strings, for instance, I would like to be able to distinguish between, say, a 0.009 string and a 0.010. That gets pretty close to the caliper's stated precision, so that might be a tall order but it's worse than that.For instance:Actual Feeler Gauge / Caliper Reading0.026" / 0.016"0.018" / 0.0095"0.015" / 0.007"I reached out to customer support, who gave me a refund without a hassle.I gave two stars simply because they don't *seem* chintzy and customer support came through, but the most important thing in a set of calipers is accuracy.Other reviewers seemed to get fairly accurate measurements with feeler gauges, so I'm going to order one more time and see how accurate the new ones are. If they're accurate, I'll assume my calipers were a fluke and raise the rating.

Not an expert, but have watched an AvE BOLTR or 50.Came in a decent carrying case, stiff edges, no padding inside, but it's nice to have a case. The tool itself has a decent weight to it, doesn't feel like I'm going to bend it easily or damage the components. The thumb wheel is a bit loosey goosey, but it moves as expected if you press down a bit and is steady in it's tracking on the display, which was actually easy to read in full sun.The inside and outside caliper measurements are well ground, no stray marks or signs of dull tools in the making to my untrained eye. The buttons do what you'd expect and it's nice that to turn it on you just have to slide the thumb roller. Only reason I didn't give it five stars is that it doesn't display in fractions the imperial measurements. It's easy enough to convert, but I like really easy.I used it to validate drill bit sizes both imperial and metric, it was spot on to 10,000th of an inch.I didn't test the waterproof rating, but It seems pretty buttoned up.

I would have given it 5 stars but, I received it with a dead battery..[If you don't have a Battery CR2032 Don't worry just take the one out of your motherboard it's the same.{ PC only}]. The unit hits the top of the case and turns on added some foam it worked. Now about the tool. So far I'm Impressed. The Material, weight, feel and design. I've paid over 5x more for less the machining has been done properly Checked it with my straight edge. I buy Tools for my job as needed, about every week. It Iook's and feel's expensive. I hope it preforms as good as it look.. Will update latter.. only flaw [So Far] is the case put some foam in it keeps the tool from moving around...

This metal caliper is much better than any plastic caliper I have used. The mechanism moves easily and smoothly even after months of use. The battery was easy to change once I figured out I needed a tiny screwdriver (from an eyeglasses repair kit) to unscrew the cover to the battery compartment. And I liked that it could use a variety of replacement batteries. Luckily I had one battery that would fit it when I needed to replace the battery.I'm very pleased with this caliper. It's accurate, easy to read and use, and not to bulky.