Hi guys, I just bought an used iPad Air 2 for my mom to browse website and read ebook. The iPad is a cellular version with OS 9.2.1 installed, however I can't find the cellular setting within the Settings app. The previous owner also stated in his ad that this is an iPad wifi, so I am not cheated. He told me that when he first bought it, he inserted a sim card and it ran without trouble. Later on he didn't use the cellular since he used this iPad at home only using wifi, so the next time he put a sim card in, it didn't work. I check on Apple activation and the site confirms that this is a cellular iPad Do you know how to fix this problem? I don't really need the cellular but it bugs me. Thank you.