Download iOS 12.1.3 Build 16D39 IPSW Firmware Restore Files
Download the IPSW iOS 12.1.3 (Build 16D39) firmware file released at 22 January 2019 intended to restore iPhone 8 (GSM) via iTunes. IPSW iOS 12.1.3 build 16D39 is unsigned by Apple to update Apple device software.