The King 4B trombone has a classic large bore symphonic trombone design. Because of the .547 bore, it has a very open feel and is best suited for the lower parts in a jazz band as well as for symphonic playing. This is a very versatile model of trombone. A bronze brass bell comes standard on this model to offer the performer a quick response and a warmer tone.
The King 4BF trombone has a classic large bore symphonic trombone design, with the advantage of having an F-attachment trigger to extend the range of the instrument and help with those difficult “extended arm” passages. This model features a .547 bore and a bronze brass bell to offer the performer a quick response with a warm, full tone.