An accessory for the broader among us, the Sleeping Bag Expansion Gusset (or Expander) is a simple, clever way of adding wiggle room to all ONE PLANET sleeping bags. This zip-in extension can be left attached to your bag ready for the next use, and adds an extra 25 centimetres in diameter to the shoulder of ONE PLANET sleeping bags. (All models except the Camp Lite series.) The design tapers in towards the foot to maintain your sleeping bag’s shape and performance.

Note: we use YKK zips on our sleeping bags. These zips can vary up to 2% in length/stretch. The Expansion Gusset is shown attached to a sleeping bag: the sleeping bag is not included.

  • Two versions: -5°C and -10°C
  • 20 denier Vapour Vent fabric
  • Fits all ONE PLANET sleeping bags, except the Camplite Series
  • YKK zips
  • Filled with 700-750 loft Hydrophobic Down


  • Fabric: Our Sleeping Bag Expanders are made using lightweight and highly breathable 20-denier Vapour Vent fabric, a good, all-round durable shell with a beautiful feel. This strong, compressible and highly breathable fabric is ‘downproof by construction’: the tight weave keeps the down in but allows water vapour to escape. This reduces the possibility of clamminess and allows the down to loft fully for maximum performance.
  • Down Specifications: Sleeping Bag Expanders are filled to order with our great value 700-750 loft Hydrophobic Down only


  • -5C: 257g
  • -10C: 296g