PHILADELPHIA (CBS) — Slurpee fans can get their fix on at 7-Eleven as the convenience store is allowing customers to fill up any size cup they bring in for $1.50.

Mother, Daughter Kayaking Delaware River In Support Of Breast Cancer Research

The Bring Your Own Cup Day offer takes place Friday and Saturday from 11 a.m. until 7 p.m. at participating 7-Eleven locations.

7-Eleven has rules for the cups customers are allowed to bring in. The cup must fit upright within the 10-inch hole, must be food-safe clean, must be watertight and only one cup per person.

Dîner en Blanc Takes Over Popular Philadelphia Park, Makes History

Customers can share a pic of their cup creation on social media with #BYOCupDay.