On May 28, 12:15*am, The Other Mike
wrote:

Ryanair supply bags that comply with their own spec which is different
to anyone elses and cost about 80 quid.

Ryanair's size is 55x40x20, larger than some "legacy" airlines.
easyJet used to do the same, and only changed to "IATA size",
56x45x25, which is the largest permissible by UK law, when they
changed most of their aircraft for Airbus 319s which have larger
overhead bins to cope with it. If you get one of the old 737-700s
(only two left, both based at Luton and will be gone by November)
there tend to be problems because the bins are too small and bags of
that size have to go lengthways, taking up a lot of space.

Neil