TAMPA, Fla. (WFLA) — Frontier Airlines is offering a one-day sale for Earth Day, allowing travelers to purchase roundtrip domestic flights and one-way trips to Puerto Rico for just $43.

Frontier, which claims to be the most fuel efficient than any other U.S. airline, is offering the sale for purchases made before 11:59 p.m. on Monday. The sale is valid for nonstop travel on Tuesday and Wednesday, through Jun. 30, 2024; and Aug. 15, 2024, through Oct. 31, 2024.

“Our constant dedication to enhancing fuel efficiency and reducing our environmental footprint enables us to maintain our position as America’s Greenest Airline,” said Tyri Squyres, vice president of marketing, Frontier Airlines.  “From our modern, ultra-efficient all-Airbus fleet and lightweight seats to a focus on highlighting threatened and endangered animal species on our plane tails, green is in our DNA.”

“In one year, Frontier saved 133 million gallons of fuel — the equivalent of removing 15 billion plastic bottles from production or 263,000 cars from the road for an entire year,” Squyres added. “Our customers are our partners in sustainability, and we are celebrating them with this special Earth Day fare.”