The ones which I took with me from an Alitalia flight had those metal fasteners on as well. If anyone from Alitalia's reading this, I took them in case I got motion sickness on those flat escalator things - you know the ones - for people who are either too lazy to walk or want to run down them to see what it would be like to be Lynford Christie (or is that just me
)
In that other thread someone mentioned sandwich bags with handles that tie-up - YUCK!