LSTN Headphones Delta 1 intl flight ques.
I had been flying AA (EXP) but am switching to DL. I flew in D1 rt JFK-ZRH-JFK, the LSTN headphones were nice, but I was perplexed as to why they didn't collect these at the end. AA issues Bose hps (on some flts.) but makes a big fuss about collecting these and verifying the count. Are the LSTNs complimentary (=free to keep)?