Contrabass Oboe
The contrabass oboe is a double reed woodwind instrument in the key of C or F, sounding two octaves or an octave and a fourth (respectively) lower than the standard oboe. (source)
The contrabass oboe is a double reed woodwind instrument in the key of C or F, sounding two octaves or an octave and a fourth (respectively) lower than the standard oboe. (source)