Birchbox is expanding its offline footprint.

Beginning Friday, the sampling service will pop up in seven flagship Gap locations across New York City, San Francisco, Chicago, Los Angeles and Houston until the end of July. Customers can build their own Birchbox, test new products or purchase exclusive subscription starter boxes for men and women.

Birchbox and Gap first teamed up in 2014 for a special offer in subscribers’ December boxes, and partnered again in March on a limited-edition babyGap box for new moms.