Welder Series         DJ6-1、DJ6-2、DJ6-3 Optical Theodolite         FSJ Electronic Theodolite         DS3 Levelling Instrument         DSZ3, DSZ3-A Automatic Level         PD-3 Hand Laser Range Finder         HG-188, 288, 888 Ink Line Instrument         HWWG-01A Steel Position Detector (U.S Technology)