What's the noun for duplicate? Here's the word you're looking for.
duplicate
One that resembles or corresponds to another; an identicalcopy.
(law) An original instrument repeated; a document which is the same as another in all essential particulars, and differing from a mere copy in having all the validity of an original.
“I know that the thought of extra spending and unnecessary duplication of phone number listings might grate on the minds of those tasked with making sure dollars are spent right.”
“The artist's latest painting is a flawless duplication of the original masterpiece.”
“The photographer was amazed at the duplication of the two models, as they looked exactly alike.”