Broadening its move into the world of 4K and Ultra HD, Roku on Monday said that TV-set maker TCL plans to introduce 4K-capable Roku TV models in the U.S. this spring.

The over-the-top tech firm also said it will introduce a Roku TV reference design that bakes in support for HDR (high dynamic range), a technology that brings more pop to 4K and HD video.

Roku launched its Roku TV licensing program two years ago, and introduced its first 4K-capable device, the Roku 4, in October. Roku said it had sold 1 million Roku-powered TVs at the end of 2015 (good for an 8% share in the U.S., based on IHS and Roku data). Roku’s TV OEM partners will soon offer nearly 60 Roku TV models in all (up from nearly 40 models today), the company added.

Other Roku TV partners include LG Electronics (for a limited release during the 2015 holiday buying season), Haier America, Sharp, Hisense and Insignia, which is Best Buy’s in-house brand. Roku noted some of its other TV partners will offer 4K-capable Roku TVs later this year.

Roku said it will expand its distribution of Roku TVs to Mexico in the first half of this year, complementing current distribution of those devices in the U.S. and Canada. Roku TVs carrying the Insignia and Sharp brands were launched in Canada last fall.

On the HDR front, Roku will enable that technology by integrating Dolby Vision into its new reference design. It will also include support for the HDR 10 standard, the company said.

Roku plans to show off the new 4K UHD TCL Roku TV at Tuesday night’s Pepcom event at the Mirage Hotel in Las Vegas.