Love it or hate it, Slurpee is an iconic frozen American drink — and it’s about to have a big birthday.

The 7-Eleven staple is turning 50, and to celebrate the milestone the retailer is letting its fans have as much Slurpee as the cup of their choice (within reason) can hold for $1.50 for two days this week. 

On Friday March 18, and Saturday, March 19, between 11 a.m. and 7 p.m., customers can fill one “cup-like container, which must fit upright through an in-store display with a 10-inch diameter hole. Cups cannot be more than 9 inches wide and 11 inches tall and must be leak-proof, safe and sanitary. That means no trash cans or trash bags, kiddy pools or kitchen sinks,” according to 7-Eleven.

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It’s the second annual 7-Eleven Bring Your Own Cup event, and this year it's lasting for two days instead of just one.

“Last year’s BYOCup Day was a huge hit, and because this year is the big Slurpee Fiftee celebration, we added a second day so more people can get in on the fun,” said Laura Gordon, 7-Eleven vice president of marketing and brand innovation. “We saw just how creative Slurpee fans can get during the first BYOCup Day. They filled drums, kettles, fishbowls, helmets and teapots. I can’t wait to see what they bring this year.” 

Anyone wishing to share their creative and crazy cups, can use the hashtag #BYOCupDay on social media. 7-Eleven also just launched a website completely dedicated to the drink to mark its 50th year,