The Apple Watch’s diagnostic port has been a mysterious part of the wearable lineup since its first model, but the new Series 7 officially ditches the six-pin port entirely.
Intended for internal use for diagnostics, the port wasn’t officially acknowledged on Apple’s website or documentation. But the diagnostic port briefly hinted at the possibility of expanding the Apple Watch with hardware accessories.
The most famous of these was the Reserve Strap, which attempted to use the port for extending the battery life of the Apple Watch by incorporating extra batteries into a specially made band that would slot directly into the diagnostic port. The port actually offered faster charging than Apple’s own magnetic cable, too.