Starrett S229FZ Telescoping Gauge With 1 Telescoping Arm Set, 1/2" - 2-1/8" Range, 2-3/8" Handle Length, 3 Pieces

Telescoping gauges are used for determining the true size of holes, slots, and recesses up to 6". The ends of both contacts are hardened and ground to a radius to allow proper clearance on the smallest hole the gauge will enter. These tools must be slightly "rocked" in the hole being measured to ensure that the tool is on the proper diameter before it is locked and withdrawn. The final hole size is obtained by measuring over the gauge contacts with a micrometer.