That is the question!!!!!( I purchased the silver one with vertical grooves)
I ordered 2 as the dimensions stated with the statement "(including all parts) " convinced me that it will be ok as hand luggage for my upcoming Ryan air flight.
Well, they arrived today and the real dimensions are 56.8 x 37.5 x 21.5. Which in no way satisfies ryanairs requirements. The things is, I like them, they are lovely cases, so I investigated whether there was any "flexibility" with Ryanair.
There certainly isn't any guarantees, and nothing official, but I did find a youtube clip of someone (it's not in English so I can only go by what I can see not hear) measuring one of the actual RYANAIR metal cages at the airport.
There seems to be a bit of flexibility there, as the measurements were 57.5 x 43 x 22.3.
I think I might risk it, it is very annoying of the vendor though as they clearly either can't use a tape measure or they lie. I actually purchased them from another website and they were in the "approved by Ryanair" section, this then linked through to amazon for payment, so if it isn't accepted I might have to sue under the trade descriptions act.
Anyone else already travelled with one of these cases and want to add any further information? Or know about the measuring cages, I am flying from Stansted!