Download iPadOS 9.2.1 Build 13D15 IPSW Firmware Restore Files
Download the IPSW iPadOS 9.2.1 (Build 13D15) firmware file released at 19 January 2016 intended to restore iPad 4 (WiFi) via iTunes. IPSW iPadOS 9.2.1 build 13D15 is unsigned by Apple to update Apple device software.