Prebuilt Sets: Prebuilt sets are sets that are preowned and are currently available built in our store. They may be missing parts, be partial sets, or have color swapped pieces. Please ask if you have any concerns about a set before purchasing. They are sold AS-IS and can't be returned or exchanged. Certified Sets: Certified sets are preowned sets that have been disassembled. All parts have been counted and we guarantee that the set is complete. Should you find something is missing, we will replace it. The original instructions are included. Some sets are brand new with only the box having been replaced; these sets will have a “Sealed Bags” label on them. Retired Sets: These are new-in-box, never built sets that are no longer available on LEGO.com.
