Carl’s Jr. will become the first fast-food chain to sell a CBD-infused burger. The company announced in a tweet that it will begin selling a burger, named Rocky Mountain High Cheese Burger Delight, with “CBD-infused Santa Fe sauce” at one location in Denver, which will only be available on Saturday in celebration of April 20, a significant day in cannabis culture.

“4/20 only: We’re dropping our Rocky Mountain High Cheese Burger Delight with CBD-infused Santa Fe sauce at one Denver location only. #rockymountainhigh,” the company tweeted.

According to the Denver Post, the burger doesn’t contain anything that is illegal at the federal level (the sauce will be infused with five milligrams of CBD). The CBD in the sauce will come from hemp, rather than THC. Carl’s Jr. said in a statement that if Saturday’s testing goes well, it’s possible the sale of the burger will be expanded.

“In partnership with Bluebird Botanicals, we have done our due diligence and are bringing this to our consumers in a safe and delicious way, and we’re thrilled to be testing on April 20, 2019,” Carl’s Jr said. “We are currently testing at one store in Denver, and there is potential to expand as regulations allow.”

“CBD is one of the hottest culinary trends right now. What better place to test this new burger than in Denver, a city that has been a trailblazer in the CBD movement.”

Sales will begin at 6 a.m. for the new CBD-infused burger, Customers will be limited to two burgers and must be at least 18 to purchase one, according to the newspaper.