A belt bag dubbed the “perfect travel accessory” is going viral with thousands of shoppers, who have even given the bag its own hashtag (it’s #lululemonbeltbag, if you’re interested).

The $59 Lululemon Everywhere Belt Bag has become one of the most popular fitness and travel accessories on the market right now, and it repeatedly sells out both online and in Lululemon stores.

The water-repellent accessory has a number of features that have prompted shoppers to label it their “favourite”, including a handy exterior zippered pocket to keep keys handy, as well as interior pockets for everything you want to keep safe.

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It also has an extendable strap so you can either wear the bag around the waist or across the body for a more retro-inspired look.

The bag is available in either a 1L or 2L size on the Lululemon website, as well as a number of different colours like hot pink, black and white.

It is 9cm x 5.5cm x 13cm (7.5” x 2” x 5”), making it the perfect size for your wallet, keys and iPhone, with many saying they love wearing it when travelling on holiday or out on hikes.

“Favourite purchase. I use it everyday. Worth it!” one shopper wrote in a review.

“This is a great bag to use around all the time. It’s perfect for running errands and keeps your phone, wallet, keys, and a few extra items,” another added.

A third said: “This bag is a game changer specially as a mum of three. It helps me be able to carry and teach the essentials when we are out and about without having to dig through a purse or backpack. Love it!”

While a fourth added: “Everyone needs one. The perfect accessory to complement an outfit while carrying all your essentials hands-free! I use for this for all occasions - bike riding, hiking, traveling and running errands. It’s the best invention to look cute and keep all your necessary items on you”.

Many say they own the bag in various different hues, with others saying they have used it travelling all over the world.

Thanks to its water-repellent, nylon mix fabric, it’s as perfect for rainy days as it is sweaty workouts.

For more information and to shop the bag that keeps selling out, head to the Lululemon website here.