Temotuf TFME3002160A M16.0 X 1.00 Metric Fine Double Ended Screw Plug Gauge - Go & No Go
Made of bearing steel GCr15, HRC58-62
Typically used to check the internal threads of products
The Go thread plug gauge must enter and pass through the full-threaded length of the product freely and the No Go thread plug gauge should never fit into the product for more than 3 turns