So this might be a stupid question... But I was told about dive bottles for sale (the seller owns a CZ200 but is getting rid of everything )... So when I went to see the bottles, I noticed that they are actually Afrox cylinders (the black cylinders)... Apparently this person has been using them for over 3 years for his pcp. It's the first time I've heard of anyone using them, so naturally I'm skeptical... According to him the pressure rating is about 240bar? So I don't know what to make of it... Any thoughts on this??