This is an eInk from the Kobo line. It's available in both black and white, with the black one being here:
Normal price is $79.99, this particular store is offering it at close to 50% off. Site policy is that you get free shipping over $40 so any random tiny item will do it.
This is an epub-compatible (and Adobe-DRM compatible) reader that uses the Kobo store by default. Its claim to fame is an exceptionally tiny 5" screen, making it not much bigger than a mobile phone.
It doesn't light up and it doesn't have the best eink screen out there, but if you want the most portable eink reader that you can get, this is probably the one for you.
From this particular seller, a purchase of a Kobo also gets you 3 electronic copies of the Bible (apparently you have to register your device wirelessly to get that). Their Kobo page also says they donate $5 to sponsor a girl rescued from the sex trade in Cambodia for each device sold.