A:Answer Not sure if by "nozzle" you are referring to the jack or the ear tip.
If it's the jack, it uses the typical 3.5mm diameter, it is round, and straight.
Regarding the ear tip, it is oval (a Klipsch design feature). Several sizes are included in the package (they are interchangeable, and also available aftermarket from Klipsch, and probably Amazon): Large, Small, Small flanged (kind of like a small scoop of ice cream on top of a larger one), and the pre-installed size Medium.
The tips have no rim, but are at a bit of an angle to the body of the earbud. The tips themselves are thin silicone rubber, and are flexible, which is in contrast to the rigid (plastic?) earbuds that iPhones come with. For some people, it takes a little time to get used to a bit of a press fit in the ear canal. And maybe some people are just bothered by the feel. I like that I can return this kind of item to a Best Buy store within 2 weeks for a refund if they don't work out.
