The iPad Air 2 (Cellular) comes with a firmware identifier iPad5,4. It has a Board Configuration of J82AP and a Board Platform of t7001. The CPID and BDID are 28673 and 2 respectively.
IPSWDL.COM is a website that provides download links for IPSW files, which are used to install or restore firmware on Apple devices. These files are sourced directly from Apple's servers.