Online shoe retailer Zappos has announced a slew of brand collaborations in celebration of its 20^th anniversary.

Zappos has planned seven brand partnerships to be unveiled over the course of the year. The first official collaboration will be with Birkenstock for a line of limited-edition emerald green sandals. Only 225 pairs of the shoes will be available for purchase when they launch later this month.

“At Zappos, we’ve built our company on relationships, and it’s through this strong core value that we’ve been able to successfully grow to where we are today at the ripe young age of 20,” says Joseph Grusman, general manager, ec-ommerce marketing, Zappos. “We love all the brands we carry, and we constantly strive to show this to them in new fun ways, but what we’re most known for is how we prove our love for our amazing customers. With our 20th anniversary plans, we’re excited to celebrate both in entirely new ways.”

Along with the partnerships, Zappos will also be hosting a variety of events and initiatives in honor of its 20^th anniversary milestone. Announced plans coming this year include: