PadFone2 Firmware: V11.8.3.3 Only for WWE SKU (Android 4.4)
Steps of Update:

1. Check SW version of your PadFone2*
2. Download PadFone Firmware: V11.8.3.3 Only for WWE SKU and Update version of SOP (From “Manual” Item)

※Firmware update cannot do *SKU conversion* and downgrade version.
Wrong SKU may cause update failure, You can only update your SW version on the Same SKU
*How to check SW version of your PadFone2?
Path: [Settings]–>[About PadFone]–>Build number
Example: You should be able to see the build number TW_PadFone-11.X.X.X, where “TW” means SKU.

PS: Due to this Android 4.4 upgrade would reset your device, please do refer the upgrade SOP to backup your personal data.
พระเจ้าช่วยกล้วยบวชชีกว่าจะมาได้
http://www.asus.com/th/Tablets_Mobile/PadFone2/HelpDesk_Download/