What is the best hardware ebook reader?

This e-reader changes color temperature manually or based on a schedule of your choosing. This is helpful for people who like to read at night but still want to sleep well. Light with a blue component (most colors of light including various shades of white, with the exception of pure red light) prevents the production of melatonin which is the chemical responsible for that tired feeling that makes sleeping easy. Darker warmer colors are also much more comfortable to read in dim lighting.