On New Year’s Day, Michelle Obama posted on Instagram a photo of herself and Barack Obama in festive attire: matching gold star-shaped paper glasses, a string of pearls around her neck and, on his wrist, a striking all-black watch.

The watch was notable because in recent years the former president has been seen wearing a Rolex Cellini. This one had a different and much more casual look, a recently released collaboration from the athleisure brand Actively Black and Teleport Watches.

The timepiece actually was the result of a misfortune. In July 2021 Lanny Smith, the former N.B.A. player who is chief executive of Actively Black, had his car broken into and his Hublot watch stolen. Instead of buying the same model, Mr. Smith began looking at Black-owned watch brands and came across Teleport, a New York-based company founded in 2020 by the husband and wife team of Michael Porter and Trenel Francis-Porter.

Teleport makes both silicone and metal watches, and its signature feature is the lucky number seven that appears on the face of each watch (the brand website says the number represents “perfection and completion”). Mr. Smith bought one of Teleport’s watches and said he was impressed with it.

“The quality was just amazing,” he said in a recent phone interview. “It reminded me of what I’m trying to do with Actively Black.”

He posted about the watch on his personal Instagram feed, which has more than 10,000 followers, and Teleport’s owners reached out to him. After corresponding for a bit, the two brands decided to collaborate on a sports watch, which was released on Christmas Day.

The result was a chunky, water-resistant watch with an octagonal bezel and a round dial, in black. It has a silicone band and a black stainless steel case, with a Miyota quartz movement. The watch retails for $300, and is available in 41 millimeters and 34 millimeters; it is part of a his-and-hers set but can be purchased separately.

Mr. Smith said he was surprised by the Obamas’ photograph. “He could have access to the Rolexes, to any of the watches he wants,” he said. “So when I saw the watch on his wrist, I thought, ‘That’s amazing. He’s wearing it.’”

After the photo was posted, the mysterious black watch became a quick sensation and, once Mrs. Obama’s stylist identified it, the model sold out. A second drop now is available to pre-order on the Actively Black website and Mr. Smith said he expected them to begin shipping by April 20.

Mr. Smith said many young Black men grew up hearing rappers and entertainers talk about Rolexes or other expensive brands, and believed that it was the only mark of success. “I want to change that narrative,” he said, “and promote buying a Black-owned watch brand that cares about our community.”