Amazon's £10 Ryanair approved cabin bag has 'enough space for a five day holiday' If you're planning a trip abroad and need the perfect travel bag that fits under the plane seat, shoppers are loving Amazon's duffel bag. It's 'super roomy' and costs less than £10.The bag measures 40x19x25cm and fits perfectly under the plane seats. It meets Ryanair's strict travel luggage rules which allows you to take a free cabin bag measuring 40x20x25cm.The duffle bag is available in 28 different colours, from classic black to fun patterned options.