Holds fly line plus backing and provides drag on running fish. For trout it mostly stores line; for saltwater the drag and backing capacity are critical.
When to use it
Trout (line storage)
Saltwater flats (drag + backing matter)
Any fly fishing
Strengths
Smooth sealed drags for salt
Large arbor picks up line fast
Backing for long-running fish
Weaknesses
Trout reels are simple; salt reels get pricey
Must be matched to rod line weight
Key facts
Best species: Trout, redfish, bonefish, tarpon, snook
Drag: Sealed disc drag for saltwater; click-and-pawl fine for small trout
