I would like to use the E-reader as a second monitor, which one shall I buy?

To use the e-reader as the second monitor of the computer, we recommend Max Lumi and Max Lumi 2 as they both have a 13.3" screen which is suitable for web browsing, word/excel editing, and reading documents. 

The main difference between Max Lumi and Max Lumi 2 is that the Max Lumi comes with an HDMI port and USB C port. However, the Max Lumi 2 only comes with a USB C port. Therefore, it is able to use the Max Lumi as a second monitor by using the HDMI connection. Please note that the HDMI connection is only applicable for Windows OS, we are afraid that the macOS and Linux are not supported.

Since Max Lumi 2 does not come with the HDMI port, the HDMI connection is not supported. However, you could still use third-party apps to turn the Max Lumi 2 into a second monitor. There are a couple of third-party apps. For Windows users, we recommend the Spacedesk app. For macOS users, we recommend Timeviewer or XDisplay. 

Besides the Max series, all BOOX models are able to turn into the second monitor of the computer.  However, their screen size is a bit small for monitor for PC. So we recommend the Max series.