I have just been given details of the above card. It is easily obtained by filling out a form ( not long winded ) from the Post Office.
You receive back a credit card sized card which you produce when in an EU Country.This entitles you to free medical treatment.
It is free as you are a citizen of a member country.
Does not negate need for Medical Insurance according to info that accompanies form.
None the less it is free to apply for so worth having and taking on holiday.