An optional extra for the broader among us, this zip-in expansion gusset adds an extra 25 centimetres in diameter at the shoulder of One Planet bags, tapering to nothing at the end of the side zip of the main bag. Available to fit every model and size perfectly, it is filled to match the warmth of the bag it will accompany. (Not available for the Booster, Cocoon or Stowaway.) Made of 40 denier V2 fabric, it is a simple, clever way of adding some wriggle room to your nighttime attire.