Features: Double action handles are rigidly attached to the contact plungers and are automatically self-centering. Assist in quick checking of holes, slots and recess up to 6 inch deep. The ends of both contact are head treated steel and precision ground to a radius allowing proper clearance on the smallest hole the gauge will enter. Constant spring tension delivers uniform contact pressure. Super quality, high rigidness, good wear resistance, durable in use. Specification: 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) 1¡¢Double action handles are rigidly attached to the contact plungers and are automatically self-centering. 2¡¢Assist in quick checking of holes, slots and recess up to 6 inch deep. 3¡¢The ends of both contact are head treated steel and precision ground to a radius allowing proper clearance on the smallest hole the gauge will enter. 4¡¢Constant spring tension delivers uniform contact pressure. 5¡¢Super quality, high rigidness, good wear resistance, durable in use.