Digma Citi Z540 4G Stock Firmware (Flash File) The Flash File will help you to Upgrade, Downgrade, or re-install the Stock Firmware (OS) on your Mobile Device. The Flash File (ROM) also helps you to repair the Mobile device, if it is facing any Software Issue, Bootloop Issue, IMEI Issue, or Dead Issue. File Name: Digma_Citi_Z540_4G_20161026_SPD.zip File Size: 459 MB Flash Tool: SPD Flash Tool How to Flash (install): Follow Tutorial Mirror 1 (Free)Mirror 2 (Paid)