The extraction will produce a .pkg file, which is a game dump designed to be installed on a jailbroken PS4 console .
You must download all .part files (part01 through the last part) associated with this download to extract it successfully. BatmanArkhamKnightUSAPKG-pkgps4dotcom.part09.rar
Use software like WinRAR or 7-Zip to extract the contents, starting with .part01.rar . The extraction will produce a