Pilottone (or Pilotone) and the related neo-pilotone are special synchronization signals recorded by analog audio recorders designed for use in motion picture production, to keep sound and film recorded on separate media (otherwise known as double system recording) synchronised. Before the adoption of timecode by the motion picture industry, pilotone sync was used in almost all 1/4-inch magnetic double system motion picture sound recording from the late 50s until the late 1980s. Previous to the introduction of 1/4-inch audio tape recordings were made on 35mm optical cameras and then later, with the introduction of magnetic recording, 16mm or 35mm magnetic stock. The first 1/4-inch recorder capable of recording a synch track to regulate the playback speed of the recording was made by Rangertone and was a variation on the soon to come pilotone system.