(All iPads of iOS 4.2.1 operating system, including: formerly imperfect Yue/yu, never Yue/yu, native 4.2.1, and iPad upgraded to 4.2.1 (if your operating system is 3.2.2, you can consider upgrading the system to 4.2.1 and then use this method to Yue/yu). This document includes the following accessories:)