Prestigio PSP3537 DUO Stock Firmware (Flash File) The Flash File will help you Upgrade, Downgrade, or re-install the Stock Firmware (OS) on your Mobile Device. In addition, the Flash File (ROM) also enables you to repair the Mobile device if facing any Software Issue, Bootloop Issue, IMEI Issue, or Dead Issue. File Name: Prestigio_PSP3537_DUO_SC7731_20161116_6.0_SPD.zip File Size: 775 MB Flash Tool: SPD Flash Tool How to Flash (install): Follow Tutorial (Mediafire)