7-Eleven is bringing back the "Bring Your Own Cup" promotion starting this Friday May 19th and going through May 20th.

"BYOC" is back but you need to know the rules to enjoy the day.

Your Slurpee cup must be able to fit through a 10-inch hole, needs to be safe for food, should be water tight, and only one cup per person.

It's up to you to find a bucket that fits those rules.

Getty Images

The good news, filling your cup will only cost you $1.50.

"BYOC" special runs on Friday, May 19 from 11 a.m. to 7 p.m. and Saturday, May 20 from 11 a.m. to 7 p.m.