Amazon is selling its own smart TVs.

On Thursday, the tech giant revealed its first lineup of Amazon-built TVs: the Omni Series and the 4-Series. Both models feature 4K resolution and Amazon's Fire TV operating system.

Before now, Amazon licensed its Fire TV software to third-party manufacturers like Toshiba and Insignia, but didn't make its own TVs.

The Omni Series lets users start shows, switch inputs, change the volume, and more with Alexa — without the need to use a remote. Alexa can be triggered even when the TV is

Omni Series TVs can provide live picture-in-picture from Ring doorbell cameras, which are also made by Amazon. And they connect to Amazon Echo devices.

The 43-inch Omni Series costs $409.99. It’s also available in 50 inches ($509.99) and 55 inches ($559.99). The 65-inch and 75-inch models feature Dolby Vision, and cost $829.99 and $1,099.99, respectively.

The Fire TV 4-Series is less expensive at $369.99 for the 43-inch model, $469.99 for the 50-inch model, and $519.99 for the 55-inch model. Amazon says it has "many of the same features," but doesn't support Dolby Digital Plus or Dolby Vision. It also requires the use of a remote to trigger Alexa.

Starting next month, the Omni Series and the 4-Series will be available on Amazon and at Best Buy.