Amazon added two new tablets to its lineup today. The Kindle Fire HD 6 is the more affordable of the two, priced at just $99. That's off-contract pricing, so kudos to Amazon for bringing such an affordable device in to the market. Then, there's the relatively expensive Kindle Fire HD 7, which now costs $139.

The Kindle Fire HD 6 is obviously the new kid on the block. Just like the Kindle Fire HD 7, this slate is powered by a quad-core processor, which has two cores clocked at 1.2 GHz and two cores at 1.5 GHz. There's 1 GB of RAM on both the slates, 8 or 16 GB of internal storage and USB 2.0 ports.

Both the Kindle Fire HD 6 and Fire HD 7 have 1280 x 800 resolution displays, translating to 252 ppi and 216 ppi pixel densities respectively. The duo also offer 2 MP rear and VGA front snappers. The tablets run on Amazon Fire OS 4.

While the Fire HD 6 is 10.7mm thick and weighs 290g, the Fire HD 7 is 10.6mm thick and weighs 337g.

The cheapest Kindle Fire HD 6 (ad-supported) costs $99, whereas the cheapest Kindle Fire HD 7 costs $139. The top Kindle Fire HD 6 model (no ads) with 16 GB internal storage will set you back by $134.

There's also a new Kindle Fire HD Kids Edition (costs $149), which is essentially the same tablet with an extended 2-year warranty and parental controls thrown in.