
Last week, we heard reports that a hidden "diagnostic port" was present on early Apple Watches currently in testing. The TechCrunch report indicated the port was being used for diagnostic purposes.
The port was spotted by our forum members in a number of the new Apple Watch promo videos that Apple released today.The port has a 6-dot brass contact array inside the groove for the 'bottom' strap connector slot. Several sources have confirmed its existence and placement to me. It is very similar to the connector for the Lightning connector in iPhones, as that connector currently only uses 6 of its 8 available pins. Apple recently began opening up the Lightning port for use by third parties. A source says that this port is currently for diagnostic purposes only -- but that there is nothing preventing it from being a connection port for future accessories.

Confirmed the diagnostic port is still in the ?????? band channel. Don t know if it will ship that way or not. - Matthew Panzarino (@panzer) March 9, 2015
Article Link: Apple Watch Diagnostic Port Spotted in Apple Promo Videos