China-based GEAK launched a new watch called the GEAK Watch II, that uses two round displays - an LCD and an E Ink panel, on on top of the other. The transparent LCD sits on top of the E Ink. This enables a very efficient battery life - and GEAK says the battery will last for a week with light use or 3-4 days with "moderate" use.
Both displays are 1.36" in diameter (320x320 resolution, 254 PPI, apparently on both the E Ink and the LCD). The watch connects to your phone via Bluetooth and also includes several trackers (heart rate, air quality, step counter and more).