LG X Mach K600 Stock Firmware Android Marshmallow 6.0 Updated KDZ File. Here you can Find LG X Mach Phone Official File And Complete Guide For How to install Stock ROM on LG K600 Device Just Follow Below Content Instructions. LG X Mach K600 Phone Specs And Android 6.0.x Update Operating System: Android 6.0.1 (Marshmallow) Display: