- Double-action handles are firmly connected to the contact pestles and automatically center themselves, ensuring repeatable, centered contact during measurements. - Helps quickly check holes, slots and recesses up to 6 inches deep, enabling rapid assessment of deep features. - Built for durability and reliability with high rigidity, good wear resistance, and overall long-term use. - The ends of both contacts are made from head-treated steel and precision-ground to a radius that allows the correct leeway in the smallest bore that the gauge penetrates. - Constant spring tension ensures even contact pressure for consistent readings across checks. - Compatibility and use: Designed for use with standard bore gauges and inspection tools that employ contact pestles, suitable for quality control and engineering environments. Use scenarios - Inspect engine blocks, transmission housings, or other components with deep holes up to 6 inches to verify bore depth and alignment. - Check bore clearances and slot dimensions in machinery during QC and assembly processes. - Center probes quickly in recessed features during calibration, setup, or rework tasks to ensure accurate measurements.