telophase--how urgent is this question? I can ask my mom, but unless she calls, it'll have to be by snail mail (for complicated reasons I don't have her phone # and it's an international call) and it'd probably be about two weeks before any response would reach me.

I do know that the closure used to be on the other side and then they switched over, I think in response to Chinese custom filtering into the country, or something. oyceter might know more, but I'll check my sources and get back to you tomorrow evening (I have a guest over today).