Yeah Rusty's correct the NOS means "non oval pipe" in the Wings world. But to the rest of the world NOS usually is "new old stock". Go fig. Also on a side note I had the dealer that I bought my bike from and he told me his parts guy made a mistake and had purchased a new Akra exhaust (header, pipe, carbon heat shields, the whole nine) and was trying to sell it to me at his cost because he said it wouldn't fit the new 2014's. Not sure why it won't fit I'd be curious to hear why, or if he might be mistaken should someone want to research it.