i found this today, havent seen to mentioned in any of the extended battery forums yet, so hope fully some out there has used it. same size with nfc, +660mAh more then stock. could it be legit?
Sproting NFC 3360mAh Extended Slim Battery for Samsung Galaxy S4 SIV s IV I9500 | eBay
Sproting NFC 3360mAh Extended Slim Battery for Samsung Galaxy S4 SIV s IV I9500 | eBay