The phones within Giffgaff's Pre-Owned Range would come in a generic (plain) box and supplied with a data/charging cable. No other accessories would be supplied with a Pre-Owned phone (like earphones or wall charger for example).
All Giffgaff's Pre-Owned phones come with a 6 month Giffgaff warranty and no quibble returns and are fully tested/data cleansed. If you are not happy with your purchase within 21 days of delivery, for any reason, you can return your phone back to Giffgaff for a full refund. How to return your phone when you change your mind
Giffgaff think you should be free to do what you like with your phone, so every phone purchased from giffgaff is completely unlocked and will stay that way. This applies to iPhone, Android, BlackBerry, Windows Phones - the lot. Your potential Mobile Phone purchase would be ready to accept any network Sim card.
For more information about buying a phone from giffgaff, please follow this link to view. Thank you.