YFB-621 F Tubas
5th Valve Slide
![](/en/files/B983C070293E4A3D808AB472CF67226E_12074_240x110_683b5f108535fe14120964443b0fa37b.jpg)
A 5th valve slide extension supplied with the YFB-621/621S allows you to change between "longer half step down" or "longer whole steps down".
A 5th valve slide extension supplied with the YFB-621/621S allows you to change between "longer half step down" or "longer whole steps down".