Chinese artist and dissident Ai Weiwei—who is known as much for his activism as for his art—once said, “My definition of art has always been the same. It is about freedom of expression, a new way of communication. I don’t think anybody can separate art from politics.” Accordingly, the prolific contemporary artist’s works have often dealt with political themes.

Weiwei’s Untitled Bicycles, a set of 60 stainless steel bicycles, is no exception. The custom-made bikes—which the artist says symbolize the innate human desire for free will in expression and mobility—were first exhibited during the Brooklyn Museum’s 2014 retrospective Ai Weiwei: According to What? Now, the fully functional two-wheelers are available for sale. In addition to being powerful statements, the bicycles, which are priced at $27,500 and available exclusively through the museum, feature stainless steel bodies, white tires, and seats imprinted with an image of Weiwei’s face. Each example also comes with a stamped and numbered head tube and a certificate of authenticity. (AiWeiwei.Edition@brooklynmuseum.org; brooklynmuseum.org)