Today’s best deals: History books, balance ball chairs, and more

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You’ll find a selection of the day’s best deals below, but for more, be sure to visit Kinja Deals.
Kindle history sale
Stop me if you’ve heard this before, but Amazon’s running a big sale on Kindle ebooks, today only. This time around, you get your choice of over two dozen history books, including the story of the secret female pope and a dive into Russia’s hacking capabilities (timely!). Click here to see the rest of the titles, all of which are on sale for $4 or less.
Gaiam balance ball chairs, $55
If you’ve resolved to get in better shape or improve your posture in 2017, these discounted balance ball chairs can help you get it done without any real time commitment.
Amazon is offering the iconic Gaiam balance ball chair in a variety of colors for $55, today only. That’s one of the lowest prices ever listed, and about $15-$25 less than usual. If you’re on the fence, check Lifehacker’s impressions of the chair for an in-depth review.
Etekcity desk lamp with USB charging port, four color temps, and LCD display, $30 with code 9RY2VFM4
$30 is a solid price for any LED desk lamp, but it’s one of the best we’ve ever seen for a model that includes a USB charging port and adjustable color temperature, which can seriously boost your productivity. Hell, it even includes an LCD display that shows you the time, date, and current air temperature, which nobody ever asked for, but actually seems kind of cool.