Three-time ACM Awards Vocal Duo of the Year Florida Georgia Line are celebrating a massive milestone. Their debut single "Cruise" is the first-ever country single to earn diamond certification from the RIAA -- that's 10 million copies sold.

“We are blown away and couldn’t be more honored by these milestone moments," FGL's Brian Kelley says in a press release. "Our fans keep us doing what we do and made this possible!”

In 2014, "Cruise" became the best-selling country digital single of all time. It also overtook the record for the longest No. 1 on Billboard's Hot Country Songs chart.

“The past year has been such an incredible ride. Each time we release a single, we can only pray that people are going to respond positively, and thankfully, they did," Kelley's duo partner Tyler Hubbard adds. "We have the best fans in the world, by far!”

Florida Georgia Line have so far released two albums: their double-platinum debut, Here's to the Good Times, and the platinum-selling Anything Goes. Their first eight singles, through "Sippin' on Fire," each reached No. 1 on either the Hot Country Songs or Country Airplay chart, and have all been certified at least platinum. Their two most recent singles, "Anything Goes" and "Confession," have each reached the Top 5 on the Country Airplay chart and the Top 10 on the Hot Country Songs chart, and "Anything Goes" has been certified gold.

Hubbard and Kelley are currently at work on their third studio album.

“I think this album is going to be our deepest album,” Kelley tells The Boot. “It’s gonna be our strongest, and we’re pushing ourselves on all levels: vocally, lyrically, melodically.

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