Internal Micrometer with a measuring range of 5 mm to 30 mm and a precision of 0.01 mm, featuring a clear laser marking line for easy reading. Note: In normal use, calibration is not required; calibrate only when heavily worn. Key benefits - Accurate, repeatable inner-diameter measurements with a locking device and a ratchet stop for intuitive, consistent readings. - Durable construction for shop environments: stainless steel body with a chrome-plated surface for wear resistance. - Versatile measuring heads made from high-quality alloy for measuring various inner sizes; fine workmanship with burr-free edges. Material and build - Main body: stainless steel with a chrome-plated surface for durability and wear resistance. - Measuring heads: high-quality alloy, suitable for a range of inner size measurements; designed for precision and smooth operation. What’s included - 1 x Internal Micrometer - 1 x Wrench - 1 x Calibration Ring - 1 x Packing Box Use scenarios - Inspect bore diameters in machined parts or housings to verify critical tolerances. - Measure inner dimensions of sleeves, bushings, and cylindrical components during assembly or maintenance. - Toolmaking and precision fitting tasks that require accurate small-diameter internal measurements.