Redbox is now offering 4K Ultra HD Blu-ray disc rentals — but it’s starting with only four titles, available in limited quantities in just six U.S. markets.

The first Ultra HD Blu-ray movies available at Redbox kiosks are: Disney-Marvel’s “Black Panther,” Lionsgate’s “The Commuter,” Warner Bros.’ “The Matrix” and 20th Century Fox’s “The Martian.” Those are available starting this week at about 2,500 Redbox kiosks in New York City, Los Angeles, Seattle, Austin, Detroit, and Miami. That represents around 6% of Redbox’s total network of 41,500 kiosks across the U.S.

Redbox’s rental pricing for the 4K titles is $2.50 per night. That’s a premium over $1.75 for regular DVDs and $2 for Blu-ray discs. Redbox isn’t offering online reservations for the 4K Ultra HD discs during the test period.

Upcoming 4K titles Redbox expects to add over the next few weeks include “Red Sparrow” starring Jennifer Lawrence, “Pacific Rim: Uprising,” the 2018 “Tomb Raider” with Alicia Vikander, and 2010’s “Inception.”

“We wanted titles that would have high interest going forward — they’re all action-related and incredibly visually stunning,” said Redbox CEO Galen Smith. “As a consumer, I want to pay a slight premium to get the best possible experience.”

To be sure, 4K remains a relatively niche technology. As of the first quarter of 2018, around 9 million U.S. households — less than 10% — had a 4K Ultra HD playback device (including UHD Blu-ray players), according to the Digital Entertainment Group. Close to 35 million American homes had a UHD TV set, DEG estimates.

Smith conceded that Ultra HD Blu-ray is still a “nascent” format but pointed to recent retailer discounts of UHD Blu-ray players to around $100 — and even lower. “When we launched with Blu-ray a few years ago, it was when the price of players started to drop,” he said.

In selecting the six test markets for the 4K rentals, Redbox worked with studio partners to determine which areas overindex on sales of UHD Blu-ray discs, according to Smith. Redbox will use the data it collects to calibrate inventory and distribution of 4K titles; for the initial launch, the kiosks in the test will have “a couple” copies of the four movies, according to Smith.

For now, Redbox isn’t offering any 4K content through the Redbox On Demand digital-streaming service, which it launched in December 2017.

Disney has sued Redbox over the kiosk operator’s reselling digital-access codes for Disney movies, which Redbox pulls from the DVD/Blu-ray combo packs it purchases on the open market. (Redbox has direct purchasing agreements with the other major studios for discs.)

For the 4K disc rentals of “Black Panther,” which was released on DVD and Blu-ray on May 15, Redbox is protected by the first-sale doctrine of the U.S. copyright code. Redbox asserts that the first-sale doctrine also allows it to resell Disney digital-access codes; Disney’s lawyers, however, argue that there’s a key difference between reselling a DVD and providing digital access to copies of movies.

Meanwhile, Redbox’s launch of 4K Ultra HD rentals comes after it recently rolled out Nintendo Switch video-game rentals in six markets nationwide: San Antonio, Portland, Seattle, Nashville, Denver and Salt Lake City. All Redbox rentals, including the 4K UHD discs, can be returned to any kiosk location in the network.

Pictured above: Chadwick Boseman in “Black Panther”