DigitalMicrometers Screw Gauge are intended for measuring outside, inside, and depth, with the range of measurement from 0 to 25mm
 
Operation
ON/OFF...SET: ON/OFF and set key. Press the key for a short time it turns power on and off, press this key for a long time, set the zeroas "0,25,50,75 ". Press and hold the key, several zero values are displayed alternately. Loosen the key when one of the zero values is displayed, the zero value is the currently displayed value data.
ZERO: Zero key. Press the button. The data becomes a default starting value (0,25,50,75).
ABS...in/mm: Relative and absolute measurement conversion key metric and inch conversion key. Shortly press this key for absolute measurement and relative measurement conversion. Long pressthe key for metirc and inch display conversion. When LCD displaysthe " in " and small font " 5 " it is in inch display.
 
How to use
Before using this product, put the special battery cover key into the middle of the battery cover. Counterclockwise rotation, open thebattery cover, replace the battery, and then clockwise rotation, lock the battery cover, check the LCD screen is displayed normally olnot
Loosen the locking wrench and wipe the spindle with a clean, softcloth. Turn the quick-moving shaft, separate the two probes a certain distance, then wipe the measuring surface clean.
Turn the quick-moving shaft to move the two probes closer together. When approaching, turn the ratchet sleeve, make the two measuring surfaces together and then check the data is zero or not. lf yes, you can start the measurement. lf not, please press the " zero " key toclear the data and then start the measurement.
When the micrometer measuring surface and the workpiece is approaching, you must use the ratchet sleeve rotation, and ensure that the workpiece surface is fully flat at the same time, when hear the load beating pieces ring 3 to 5 times, stop the rotation, to ensure accurate measurement.
 
Resources:
1. A Comprehensive Guide to Digital Micrometers