SEVEN CONVERTIBLE HARDNESS SCALES: Supports HL, HV, HB, HRC, HRB, HRA, HS direct conversion. Test steel, cast iron, aluminum alloy parts without switching equipment for batch metal quality checks. HIGH PRECISION PROBE: Built-in carbide dual-coil impact body with intelligent calibration algorithm. Minimize measurement error to deliver consistent repeatable data for factory quality control. 360° AUTO ANGLE COMPENSATION: Manual calculation for tilted testing angles lowers work efficiency; integrated direction sensor auto offsets gravity errors for all orientations. Matched D-type impact head fits regular metal workpieces without manual adjustment. PORTABLE RECHARGEABLE: Supports thousands of hours continuous use with sleep mode. Compact pen-shaped ergonomic body for portable outdoor inspection. WIDE INDUSTRY MATERIAL COMPATIBILITY:Compatible with steel, stainless steel, cast iron, alloy metal. Applied to hardware casting, mold processing and mechanical labs for professional industrial hardness testing.