A photo posted to Twitter shows a sticker for prototype number 1902 out of 3000 with a return date of 08/29. The prototype identifier is D10 and notably it has 32GB of storage.
The storage level appears to corroborate a WSJ report that Apple is planning to up the storage in its base model iPhone 7 to 32GB. This would be a welcome change as may customers with a 16GB iPhone are constantly frustrated with running out of space on their device.
Apple is set to unveil the iPhone 7 on September 7th. Make sure to follow iClarified on Twitter, Facebook, Google+, or RSS for updates.