Shake Shack fans rejoice! The restaurant chain has teamed up with Square’s Caviar on-demand food delivery service to see if it’s a valuable offering. Those in New York, Los Angeles, Philadelphia, Washington, D.C., Boston, and Chicago are eligible to get any of Shake Shack’s burgers, chicken sandwiches, hot dogs, fries, and shakes delivered right to their doorsteps — and delivery is free (you have to pay for your food though).

Here’s the catch: This trial period is this weekend, from Friday, March 24 to Sunday, March 26.

Caviar describes the move as being a “pop up,” a concept where the company does special promotions for restaurants over a limited time period. What this means for Shake Shack is that you have to use Caviar in order to get it delivered. While this is good for people in those cities, I’m going to wonder which service will start delivering In-N-Out.

This isn’t the first such pop up that the Square subsidiary has done, as other restaurants have participated. It’s perhaps a good way for businesses to evaluate whether there’s any interest from customers around food delivery and if it really works for them.

So if you’re craving some Shake Shack, but can’t muster your way to the restaurant for some reason, Caviar is your solution — but only for the next three days.