It's for use in the air. These coupons were distributed among the passengers who had booked their flights before September 2004 (i.e. before the time SAS announced the introduction of a new 3-class concept) for travel after the end of October (i.e. the time when the new concept was implemented). You can hand it to a flight attendant, but it may happen that you will have to tell her/him what it is meant for, because it seems that cabin crews are also losing track of all the recent SAS improvements and developments.