SK has introduced a class between Economy and Business. On Intercontinental operations it has wider seats and better pitch than Economy and better service (food), on intra Europe flights the difference from Economy is complimentary meal and bar (in Economy you will have to pay even for water).

Service is currently called Economy Flex but will change to Economy Extra as by next year.

Bookin classes:
Intercontinental: Y and S
Intra Europe: Y, S and B

PS. I really think this info should be added to the first post. The SK Economy Extra is not like UA. On SK it is a completely different service and it costs more too.

PS2. There are no award classes for Economy Extra (strange!)