After two years of sales declines, the accessory industry is celebrating a big win. One of the industry's champions? The fanny pack – yes, really.

Total U.S. dollar sales of fashion accessories grew 4 percent in the first 10 months of the year, according to market research firm NPD Group.

A lot of that growth was spurred by one of the world's most polarizing trends.

The fanny pack, also called the belly bag or belt pack, is the functional fad from the '80s that is usually secured via a strap around the waist. Though the thought of the accessory may conjure an image of a tourist in a tropical shirt, pleated khaki pants holding a selfie stick, the trendy sack has gotten a facelift and is now often referred to as a "belt bag."

Despite making up just 1 percent of all fashion-accessories sales, the fanny pack category, which includes "waist packs," are responsible for almost a quarter of the industry's growth.

“Changing consumer behaviors are changing the way consumers everywhere think about the accessories they need,” said Beth Goldstein, fashion footwear and accessories industry analyst, The NPD Group. “New lifestyle needs will make categories like luggage, backpacks and even fanny packs popular items on shopping and wish-lists during the 2018 holiday season.”

Modern fanny packs come in various shapes and sizes. The bags have been rendered in leather, decorated with studs, and are sold by numerous high-end designers like Gucci and Calvin Klein.

Other accessory categories that experienced growth in 2018 were backpacks and luggage. There were sales declines, however, along historically key categories such as totes and messenger bags, according to NDP Group.

Celebrities like Beyoncé, A$AP Rocky, Leonardo DiCaprio and Jimmy Kimmel have been caught buckling into the human-turned-kangaroo packs along with fashion-forward celebrities Sarah Jessica Parker and Rihanna. But the throwback tourist bag isn't just a sign of modern times.

In fact, variations of the fanny pack have been around for about 5,000 years, appearing in some form of every culture throughout the centuries, according to fashion-focused website Racked.

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