Features How to Use: The inside micrometer can be expanded in a hole to be measured, locked in place and then removed to determine final hole size by the caliper measuring tool, it is very easy to get the measurement you want Good Design:The telescopic gauge has a good design, the ends of both contact are head treated steel and ground to a radius allowing proper clearance on the smallest hole the gauge will enter. Good Performance:The telescopic gauge is of excellent quality, high rigidity, good wear resistance and durable. Functions:the spring tension of telescopic bore gauge gives uniform contact pressure, can detect the inner diameter of a hole or groove; Double action rigid handle with self centering feature for quick checking of holes, slots and recess up to 6'' deep. Material: The telescopic gauge set is made of stainless steel material, which can prevents rust. Specification: Condition: Brand new Material: Tool steel Color: Shown as picture Measuring Range: 8-150mm Accuracy: 0.1 Quantity: 6Pcs/Set (ABCDEF) Scope of Application: Telescopic spring piston in the hole (or groove), can conduct inner diameter detection, used with micrometer or caliper, with knurled locking device. Package List: 1 Set Telescopic Gauge (6pcs) Package List