These depth gauge is direct reading tools, referencing from their hardened and ground bases.
They are quicker and more convenient to use than any other type of depth gauge within their ranges and accuracy.
These gauge is for longer range, and are accurate and simple to use.
Put the contact on the work to be measured and push the gauge head down until the base stops at the reference point and take your reading.
Furnished with three rounded-end contact points to cover the range.
The zero setting can be checked with the (shortest) contact in place by pushing down on a flat surface.