CHICAGO — To celebrate its 50th anniversary, McDonald’s is launching the “MacCoin,” a “global currency” that will only be offered for a limited time.

But it’s really just a coupon.

According to a news release from the company, the “first fully food-backed global currency” will be given to customers beginning August 2 when they purchase Big Macs at over 14,000 participating restaurants across the U.S.

The coin, which has no cash value and will essentially function as a coupon, can be redeemed for a free Big Mac beginning on August 3 through the end of 2018.

The company will distribute over 6.2 million MacCoins across the globe. The coins will feature five different designs: The ‘70s, showcasing the decade’s flower power; The ‘80s alluding to pop art; The ‘90s defined with bold, abstract shapes; The early ‘00s specifically focusing on the technology that was at the forefront of the turn of the century; The ‘10s MacCoin calling attention to the evolution of communication.