hello all, i apologize if this has been asked to death but i was wondering about the size of the magic band, in my experience anything that says one size fits all usually means one size fits most lol. i have a big wrist will i have a issue fitting the magic on?? and my son is considered a child at 16 but ... he's 16 lol so not the size of a child , will i be given a tiny one for him? and if so can i get a replacement free that fits?