Action cameras are a great way to capture, well, action. Designed to be both tough and low profile, they're easy to strap to your body to record your adventures hang gliding (or whatever). They're generally pretty pricey, though, with some high-end models going for hundreds of dollars. The Yi 4K Action Camera is already a nice bargain at its normal price of $121.99, and you can currently get 20 percent off the little guy on Amazon.

The Yi has all the features you'd expect out of an action camera. It can record in 4K at 30 frames per second for up to two hours on a single charge, and it can eke out 60 frames per second at lower resolutions. It can also take 12-megapixel stills, and you can share files from the camera to your phone over Bluetooth.

There's a 20-percent-off coupon on the product page you can activate to save $24.40 on the camera for a final price of $97.59. As an added bonus, you can snag a free waterproof case with it, too, by adding both to your cart and entering the promo code AXMZLVDT at checkout. The case is normally $38.59 on its own, so you're saving about $63 on the order in all. Not bad at all.

Free is a great price for the first-party Yi case, but if you're looking for more accessories, you can get a bundle that includes a case, head mount, chest strap, and more from Kupton for $30.99, and that company's waterproof housing on its own is just $12.99.

The better-equipped Yi 4K+ is on sale, too! Historically $299.99, it's down to $209.99, plus an additional $50 off coupon right there on the product page, for a final price of $159.99 — nearly half off. No free case here, but the 4K+ can record in 4K at 60 frames per second and uses USB-C for charging and faster data transmission. You can read more about the camera here.