7-Eleven wants you to treat yo’self with BYO Cup Day this March

7-Eleven is back with its Bring Your Own Cup Day, and this year it’s bigger than ever.

The event, in which you can bring any vessel of your choosing to 7-Eleven and fill it with your favorite Slurpee flavor, is being held over the course of two days. On March 18 and 19, from 11 a.m. to 7 p.m., you can bring in your container and get slurpin’ for just $1.50.

Related story Martha Stewart Just Shared Her Mom's Stuffed Peppers Recipe & This Cozy Comfort Food Meal Is a Must-try

More: 7 Slurpee flavors 7-Eleven should create immediately

There are a few rules:

1. Containers must be able to fit through a 10-inch hole, so that old cello you were eyeing is a no-go.
2. Containers must be food safe and waterproof too — specifically, 7-Eleven doesn’t want you filling up electronics, sneakers and, um, pets. Hopefully that’s a preventative measure and not a reaction to what someone did last year, but who knows? When it comes to discounted icy sugar solutions, people have been known to do crazy things.
3. The last rule is one cup per person.

More: 7-Eleven wants to help you get lucky with odd new delivery service

So don’t be the greedy one who tries to get more than your fair share of Slurpee and ruins it for everyone else — the good thing about BYO Cup Day is that there’s always another one (or two) next year.

In conclusion, 10-inch food-safe container, $1.50 Slurpees, March 18 – 19, 11 a.m. – 7 p.m. Be there, or be square.

More: 15 crazy #BYOCupDay Slurpees you need to see to believe