The term 'duplicates exactly' can be summed up as having two or more identical copies of something. This term is often used in the context of making exact replicas of an object, such as a painting or sculpture. The crossword solution for this term is 'mirrors, ' which refers to the reflective surfaces that are used to create exact copies of an image. Mirrors are also used to create optical illusions, such as infinity mirrors, which create the illusion of infinite space.