ASUS CN_ZX551ML_2.26.40.108_20160520 BY Support.HalabTech.Com.zip
ASUS JP_ZX551ML_4.21.40.209_20161216 BY Support.HalabTech.Com.zip
ASUS WW_ZX551ML_4.21.40.209_20161216 BY Support.HalabTech.Com
ASUS WW_ZX551ML_4.21.40.314_20170522 (only HK) BY Support.HalabTech.Com.zip