Photo courtesy of 7-Eleven

In honor of the Slurpee’s 50th anniversary, 7-Eleven is hosting its bring your own cup deal for a second time this year. Like in March, customers have four days to acquire the biggest cup-like object they can find to fill up with the frozen treat.

The deal is happening this Friday and Saturday from 11 a.m. – 7 p.m.

Unlike it’s annual free Slurpee day on July 11, the company charges for the BYOCup Day experience. Customers can fill up for $1.50—the average cost of a medium Slurpee drink. So the key is to bring a larger container, however, it must fit upright through an in-store display with a 10-inch-diameter hole, according to a release from 7 Eleven. The containers must also be leak-proof, safe, and sanitary. “That means no trashcans or trash bags, kiddy pools or kitchen sinks,” the company says.

And if you can’t find your own object, 7-Eleven is selling 32-ounce Slurpee fishbowls for $3.99 (while supplies last).

The promotion comes on the heels of a string of steamy days that matched heat records in the District. Friday and Saturday’s temperatures are expected to reach the 90s in the city, according to the National Weather Service.