PHOENIX - Bring Your Own Cup Day is back!

Customers can fill up on Slurpees at 7-Eleven for just $1.50 Friday and Saturday from 11 a.m. to 7 p.m.

Now before you start taking off your shoes and hats, know that there are a few rules about what constitutes a cup.

• Your cup can’t be larger than 10 inches in diameter

• It must be food-safe clean

• It must be watertight

• One cup per person

Think you improvised the best cup? Share photos of your drinks using the hashtag #BYOCUPDAY.

To browse flavors or find a participating 7-Eleven near you, visit the Slurpee website.