How To Install Stock ROM on Vertex Impress Zeon 4G (Firmware/Unbrick/Unroot)
Guide To Install Official Stock ROM On Vertex Impress Zeon 4G (Back to stock, Unbrick, Unroot and Fix Bootloop): The available firmware file name is D3998_FWPLUS_T8_VERTEX_Zeon4G_WB18LB137820V06 .