Mitutoyo Digital Caliper, ABSOLUTE Digimatic Caliper Series 500, Range: 0-4" w/ SPC output - 500-170-30 - Penn Tool Co., Inc
Amazon.com: Hornady Digital Caliper, 050080-6 Inch Electronic Digital Caliper Measuring Tool with LCD Display to Precisely Measure Reloading Supplies with .001 Inch Accuracy - Includes Storage Case & Battery : Industrial & Scientific
Gyros Digital Caliper Measuring Tool – 6 Inch Stainless Steel Micrometer Caliper - Inch/MM Conversion and Large LCD Screen – Auto-Off Feature – Electronic Vernier Calipers 2 Batteries Included: Amazon.com: Industrial & Scientific
How to stop battery drain in Digital Calipers (CR2032/LR44/SR44/A76 Battery Hack/Mod) - YouTube
How to use a digital caliper (and more) – MachinistBlog.com