Which everyday object did Marcel Duchamp use for Bottle Rack?

For his 1914 work Bottle Rack, Marcel Duchamp used a mass-produced, everyday bottle rack as a "pure ready-made."1

By selecting this commonplace object and designating it as art, Duchamp challenged traditional aesthetic standards and the notion that an art object must be unique. This approach redefined art as an intellectual process rather than a strictly material one, a concept that became a foundational element of the ready-made movement.1