When you go to offer details page and click on "Duplicate Offer", The duplicate offer will be created with copied fields from the original offer as follows:
The name of Advertiser, Offer name with suffix “_copy", Offer type; Offer Currency, Conversion tracking protocol; Price Format (Revenue and Payout), Conversion Point, Expiration Date (Automatically set as date one year from the day of Duplicate creation), Offer Status - Pending, Preview URL and Offer URL.
The “Duplicate Offer” only copies the Initial Event and Below is the list of Attributes which don’t get copied in Duplicate Offer:
(1)   Offer caps.
(2)   Creation Time of Duplicate Offer.
(3)   Banners.
(4)   The Further Payout section including “Payout for Tier” and “Payout for specific Affiliates”.
(5)   Affiliate Access Tab.