The first models produced were combo organs in early 1967. The Explorer cost $845 and was a four-octave instrument that had a dedicated oscillator for each key, and was fitted with a "flying hammer" mechanism that repeatedly made or broke the oscillator's electrical connection, giving a strumming sound like a banjo or mandolin. The Lark was a three-octave organ which shared an oscillator between every two notes. Other instruments included the "Band Organ" (a three-octave electrical imitation of a calliope), manufactured from 1968 to 1969.