What's the largest duffel that still works as a carry-on?

Domestic US carry-on limits typically max out around 45 linear inches, which corresponds to roughly 40–50L of soft duffel capacity when not overstuffed. Anything labeled 65L+ — like the Fmeida or Urtala 120L — is meant for checked baggage or road trips, not overhead bins, and reviewers consistently flag this.