Rods, reels, spare spools, lines, leaders. Never had an issue with any. Depending where you're headed take the essentials to fish (as in clothes etc. obviously) in a carry-on also just in case, at least you can borrow flies and still fish til your bags show up if something happens. One of those Fishpond travel cases held 8 rods (just in socks) and all my reels last trip, no issues, and are size legal for carry-on.