TCL on Tuesday announced that its forthcoming “6-Series” of 4K TVs will be available to purchase by May 1. The TVs were first announced at the CES trade show in January.

The 6-Series is notable for being the latest entry in TCL’s line of Roku TVs, which for the past few years have utilized the streaming device maker’s operating system as their smart TV interface. Think of it like having a Roku box baked into the television itself. Roku lends its platform to a number of TV manufacturers, but TCL, the Chinese electronics firm that’s also known for licensing the BlackBerry and Alcatel brands for its smartphones, appears to have particularly boosted sales with the partnership. The company says it is now the “number three smart TV brand” in the US.

A big reason for that success is because the TVs are often sold at relatively affordable prices, but over the past couple of years, TCL has improved the line’s reputation with picture quality as well. The 6-Series in particular is the follow-up to last year’s P6-Series TV, which garnered near-unanimous praise from reviewers and is generally considered the best TV on the market for less than $1,000.

This 6-Series TVs don’t appear to be a total reinvention of their predecessors, but they do bring a few notable changes on paper. TCL says the TVs will have 55- and 65-inch variants, where last year’s TCL’s P6 “series” was limited to a couple of 55-inch models.

The company is also touting an expanded number of full-array local dimming zones on each set. Full-array local dimming—not the less precise “edge-lit” local dimming—is usually a reliable way to improve the picture quality of LCD panels, as it allows the TV to achieve a better contrast ratio. Typically, the more full-array local dimming “zones” a TV has, the more precise control it has over its backlighting, letting it keep more of an image’s dark parts dark and more of its bright parts bright. The P6-Series TVs had 72 full-array local dimming zones; TCL says the 55-inch 6-Series TV will have 96 zones while the 65-inch model will have 120 zones.

Beyond that, the TVs will continue to support the two major HDR formats—HDR10 and Dolby Vision—and come with a sharp 4K resolution. TCL is touting a new video-processing engine for improved color reproduction and better HDR performance as well. Physically, the TVs come with a slightly more upscale brushed-aluminum design.

A TCL representative could not specify exact price points for the new 6-Series TVs, but the company said earlier this year that they would start near the same price as last year’s model, which was around $650 for the 55-inch set. That older model has dipped in price a bit since then, but with the ostensibly improved local dimming, those interested in a Roku TV may want to wait and see how much of an upgrade the 6-Series TVs are.

TCL also plans to release a cheaper 5-Series of Roku TVs, which forego local dimming but come with the same 4K resolution and HDR support; the company has not specified a price or release date for those models yet.