RS PRO Telescope Chrome Gauge Set The RS PRO telescopic gauge set. Each of the six chrome gauges is designed to provide a high level of precision in machining and fabrication application. Offering excellent ease of use, operator simply needs to expand the gauge inside the hole you're measuring and lock the plungers in place using the locking screw at the bottom of the handle. After removing the gauge, measure the distance between the ends of the locked plungers using a micrometre or a Caliper which will identify size. Two plungers under equal and constant spring pressure can be locked between the walls of a slot or across the diameter of a space. Features and Benefits - Plunger ends are radius ground and hardened - Telescopic gauges provide easy and accurate measurement of hole diameters and slot widths - Gauge body and plungers have satin chrome finish - Knurled plunger locking screw located a bottom of handle - Largest diameter 150 mm - Smallest diameter 8 mm Applications - Automotive - Machining - Fabrication - Workshops - Manufacturing