Abbreviation for New in Box which should mean the reel has no shelf wear from age and never used. It should also be in the original Mint condition box it was sold in with complete packaging including the owner’s manual, warranty cards and so on. Serial numbers are very important to determine this as well as the correct spare spool and all other components. The problem with this is a lot of people use this term that have no idea what it means. Others that do know what it means TRY to make up “Frankenstein” reels NIB. Buyers Beware!