Amyl nitrate I think, its an inhalant, look it up on erowid, I don't know much about it bc I don't know how to get them so no reason to research em. My understanding is they're really good with nitrous and sex.
Meh, theyre ok for a quick 2 minuite headrush. Especialy handy for a sneaky, short high at work or school! But not too often, you don't want to kill a shitload of braincells.