Shake Shack & Allbirds Sneakers

For one day only, Shake Shack, NYC's beloved burger joint, is collaborating with Allbirds, the company behind the world's "most comfortable shoe," to sell limited-edition sneakers at Shake Shack's original Madison Square Park location.

The specialized kicks are all-white Allbirds Tree Runners featuring Shake Shack's signature green coloring in their lining with burger emblems on their tongues. Made from sustainably grown eucalyptus trees, these cozy, spongy sneakers are popular among bustling Silicon Valley VCs and eco-conscious New Yorkers. An order of the shoes will come with three pairs of shoelaces and a specially crafted Hokey Pokey milkshake (honeycomb pieces, chocolate, toffee stirred into classic vanilla custard) that's inspired by Allbirds' New Zealand heritage.

Fans can combine their love of the two brands by purchasing the bundle for $100—as long as they get in line early. The ever-crowded fast-casual spot plans to sell the shoes from 10 a.m. to 8 p.m., or until they run out. And if you don't land a pair of Allbirds, you'll at least still be able to get your hands on a 'Shroom Burger.