Download iOS 13.3.1 Build 17D50 IPSW Firmware Restore Files
Download the IPSW iOS 13.3.1 (Build 17D50) firmware file released at 28 January 2020 intended to restore iPhone XS Max (China) via iTunes. IPSW iOS 13.3.1 build 17D50 is unsigned by Apple to update Apple device software.