Features: * LCD display of 128 64 matrix is used. * Hardness scales(HV ,HB,HRC,HRB,HRA,HS). * RS232 interface and USB to PC * Max 600 groups impact times:32¡«1 of data can be stored at internal. * Back light display has been used to make convenient or the user in poor light. * Upper and lower limit can be preset. It will alarm automatically when the result value exceeding the limit. * Material of cast steel¡± is added HB values can be read out directly when D/DC impact device is used to measure cast steel¡± workpiece. * Power is two of AA battery. Continuous working period: approx. 100 h (no back light on). * Software of PC can be installed according to the requirements of user. The function will be more powerful to satisfy the more demands of quality control and management.