The Savoia-Marchetti S.55 was a double-hulled flying boat produced in Italy, beginning in 1924. Shortly after its introduction, it began setting records for speed, payload, altitude and range.
https://en.wikipedia.org/wiki/Savoia-Marchetti_S.55
Civil operators: Marine Air Transport Co. (US), Aeroflot, Aero Espresso Italiana, Società Aerea Mediterranea.
Military operators: Regia Aeronautica, Brazilian Navy, Spanish Air Force, Royal Romanian Naval Aviation.
(Sample kit assembled by Maurizio Boverio, IPMS Italy, Milan)