iPad iOS Firmware iPad ipsw firmware download that provided by Apple, when you do the relevant operation at your own risk.

iPad Pro 2 (12.9-inch)

iPad Pro 2 (12.9-inch) Type and Models :
  • iPad7,1
    • A1670
  • iPad7,2
    • A1671
    • A1821

The signed firmware that you can restore the file by MFC Software or by iTunes.