Contrabass Saxophone

The contrabass saxophone is the second-lowest-pitched extant member of the saxophone family proper. It is extremely large (twice the length of tubing of the baritone saxophone, with a bore twice as wide, standing 1.9 meters tall, or 6 feet four inches) and heavy (approximately 20 kilograms, or 45 pounds), and is pitched in the key of E♭, one octave below the baritone saxophone. (source)