bass trombone - Bb/F/Eb/D Besson Sovereign. A great Bass Bone for any level of player. If you’re considering studying at university or playing at a professional level this bass trombone is considered a first choice. Roughly 20 years old when Hahmann valve system teamed up with Bess Sov to develop this line of trombones is now out of production. Very responsive to low and pedal range with easy airflow with both triggers. Also a best choice for a band to purchase to upgrade their bass trombone and school students serious about studying music. Few minor dents and scratches expected with age, none on slide.