UDC and LG has been showing a wrist-worn flexible OLED prototype for a long time now. They have released some new information on the display today.
The display is 4", supporting 320x240 pixels at 100ppi. The luminance is 100cd/m2, contrast 1,000:1. The whole panel is 0.3mm thick, with a steel plate as substrate, using amorphous Si TFT. It weights 8g.