The Liquid Extend was showed in a slide during the Acer press event, and the company refered to it as a "laptop kit" to convert the Windows 10 Mobile phone into a laptop. Unfortunately, Acer didn't reveal anything else about this accessory during the event, nor is there any word on a price or release date. We will post more information on the Liquid Extend when it is revealed.
In a related note, Acer announced that its previously revealed Liquid Jade Primo smartphone with Windows 10 Mobile is now shipping, and it can be bought bundled with a Continuum-based dock, wireless mouse, wireless keyboard and a PC monitor. While pre-orders for the smartphone have popped up in other countries, the Liquid Jade Primo has yet to go on sale in the US