Gently used Black Biaggi Zipsak Boost! Underseater Expands To Carry-On Bag. No damage to bag and shows no sign of wear. Expandable under-seat carry-on is an extremely versatile bag that starts off as a small easy-to-store pouch, and opens to become a 4-wheeled carry-on that slides comfortably under the airplane seat in front of you. Need more space? No problem! Your under-seater expands a full 5" upwards, to become a full sized TSA approved carry-on!