It's not often that a good old fashioned FCC filing gives the game away anymore, but that's exactly what's given us the first reliable info on the unannounced ASUS ZenWatch 3. Diagrams first found by Ausdroid reveal a circular design and a handful of minor technical details.

ZenWatch 3

The ZenWatch 3 will also feature Bluetooth 4.2, Wi-Fi b/g/n on 2.4GHz, charging at 5V/2A and a stainless steel back. The "input" reference in the graphic suggests it'll charge directly over physical contacts, like previous ZenWatches, as opposed to Qi wireless charging like some rivals. The graphic also references "customized keys," suggesting that like LG's second-gen Urbane LTE there'll be multiple keys on the side of the watch.

It's no coincidence that Android Wear 2.0 includes a complete UI redesign to better accommodate circular displays.

The move to a circular display comes after two generations of decided square watches from ASUS — both the ZenWatch and ZenWatch 2 featured rounded rectangular designs. But with the notable exception of the Apple Watch, that's the direction most smartwatches are heading. And it's surely no coincidence that the upcoming Android Wear 2.0 release features a complete UI redesign built around better accommodating circular screens. A round ZenWatch 3 would be right at home on the new platform.

ASUS has an press conference scheduled for Aug. 31 in Berlin, ahead of the IFA trade show. For what it's worth, we've also got pressers from Huawei and Lenovo on our pre-IFA calendar, so could this new ZenWatch have a refreshed Moto 360 and Huawei Watch to face off against? We'll have to wait and see.