... .3mm,2.4mm,3.0mm,4.0mm,7.2mmHardness4H, 3H, 2H,H,HB,B,2B,3B,4B,5B,6B,7B,8BLength184 ... .3mm,2.4mm,3.0mm,4.0mm,7.2mmHardness4H, 3H, 2H,H,HB,B,2B,3B,4B,5B,6B,7B,8BLength184 ... planning quality control, quality assurance and quality improvement.In R&D, coordinate each department for check the quality. The quality control ... with new clients around the world in the near future. 2H graphite natural wooden pencil