Meghan Markle loves a good designer shoe—and who can blame her? The duchess and mom-to-be has a cool, cutting-edge footwear style, most recently rocking the PVC AND cow-print trends effortlessly. One of the shoe brands she wore during her Australia and New Zealand tour, Birdies, has particularly felt the “duchess effect.” Birdies has seen a massive surge in their sales for their “The Starling” flat—a modern take on the smoking slipper in trendy velvet. People got a chance to talk to the president, Marisa Sharkey, who explained the backstory of Meghan’s love for the brand. Even better, you can still order the slipper in select sizes and colors, for $120 to $140.

Apparently Meghan was one of the first celebrities to wear Birdies after the brand debuted four years ago—way back when she was just Meghan Markle, activist and Suits actress.

Birdies sent Meghan shoes initially, but she apparently loved them so much that she started buying them for herself as well. Once the royal was spotted in public with them, the waitlist for the style grew to 15,000 people. “We sold out very quickly of our classic black style and we had people emailing every day to ask, ‘When are they coming back?’ We couldn’t have imagined anything like this.”

Even though Meghan hasn’t shied away from high, high heels during her pregnancy, the flats are perfect in case she wants to give her feet a rest while she’s been making her most recent royal patronage visits.

Here’s a look at Meghan wearing the shoes during a visit to the Rotorua’s Redwoods Treewalk in New Zealand: