COS, the London-based fashion brand known for its minimalist styles, has once again partnered with London’s Serpentine Gallery to stage Park Nights, a series of cultural events taking place from July to October in the organization’s annual pavilion, which was designed this year by architects José Selgas and Lucía Cano of SelgasCano. To celebrate the third year of the collaboration, COS has released a limited-edition backpack, the proceeds from which will benefit the Serpentine Trust. The unisex bag, which is made of white canvas with leather trim, will be available for $135 at select London COS boutiques and on cosstoreom for lucky U.K. and European online shoppers.