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MiaMily Expandable Backpack: pockets, expanding and the trolley sleeve

Created by Coolkidz Australia

The MiaMily Expandable Backpack is the parent bag of the range. It grows from 15 to 30 litres when you need it and slides over the handle of your MiaMily suitcase.

Woman wearing a Forest Green MiaMily Expandable Backpack

Specifications

  • Dimensions: 44 × 31 × 11 cm
  • Depth expanded: 22 cm
  • Capacity: 15 litres, or 30 litres expanded
  • Pockets: 11 organisational pockets
  • Material: 100% recycled polyester, water-resistant
  • Zips: YKK
  • Colours: Slate Blue, Forest Green and Midnight Black

Expanding the backpack

An external expandable pocket on the front doubles the capacity, taking the backpack from 15 to 30 litres and from 11 cm to 22 cm deep. Keep it slim for work or a day out, and expand it when you need the extra room.

MiaMily designed it to be sleek enough for work and big enough for a weekend trip, so it is useful well beyond the airport. It is made from water-resistant, 100% recycled polyester with YKK zips.

Where everything goes

  • Laptop pocket.
  • Thermal water bottle pocket.
  • Anti-theft passport pocket.
  • Sunglasses pocket.
  • Umbrella pocket.
  • Magazine pocket.
  • Padded, adjustable shoulder straps.

Using it with your suitcase

A trolley sleeve on the back slides over the handle of any MiaMily suitcase, so the backpack rides on the case instead of on your shoulders. On travel days with the original Carry On, which has no front pocket, use the outside pocket of the backpack for the things you need in a queue: snacks, wipes, a small toy and passports.

The backpack does not have a seat. It is covered by MiaMily's Limited Lifetime Warranty.

Need a hand?

If a zip, strap or seam on your Expandable Backpack has a problem, send us a request and our Melbourne team will help.

Get help with a product

More from MiaMily

Visit miamily.com.au for the full MiaMily range, or shop at coolkidz.com.au.

Details in this article are taken from miamily.com.au and were checked on 3 October 2026.

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