Earlier this month, Amazon unveiled new Fire tablets. The new models aren't really much different from the previous generation - just a bit thinner and lighter for the most part. Now Amazon is clearing its inventory, and you can get the previous-gen Fire tablet with special offers for just $39.99.
The specs weren't impressive when it was released in 2015, and they sure aren't any more impressive in 2017 - but that should be implied by the price tag. You get a 7" 1024x600 screen, quad-core 1.3GHz MediaTek CPU with 1GB of RAM, microUSB port, and headphone jack. The $39.99 model comes with 8GB of internal storage (with 4.5GB available out of the box), but the 16GB model is also discounted to $59.99. You can also use a microSD card for more storage.
Like all of Amazon's tablet offerings, this model comes with Fire OS, a fork of Android 5.0 Lollipop without any Google services or apps. Thankfully, it is very easy to sideload the Play Store, and there are a few custom ROMs available too.
This tablet should be fine for basic media consumption, but you definitely won't be able to play graphically-intensive games or do any serious productive work. Keep in mind that this also has 'special offers,' which displays Amazon ads on your lockscreen. Removing those ads isn't too difficult, especially if you already know how to use ADB.