[Easy to adjust] Double action handles are rigidly attached to the contact plungers and are automatically self-centering.Easy to adjust for accurate measurement. Professional Precision Tool Set! [Function] Assist in quick checking of holes, slots and recess up to 6 inch deep.Two spring-tensioned telescoping plungers for uniform contact pressure. [Precision Production] 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 Tension] The Telescopic gauge set has constant spring tension delivers uniform contact pressure. Locked in position by knurled lockscrew. [Widly used] Set of six telescoping gauges for measuring holes, slots, and recesses in woodworking, metalworking, machining, layout, and pattern-making applications,Super quality, high rigidness, good wear resistance, durable in use.