YFB-621 C tuby
5th Valve Slide
![](/cs/files/B983C070293E4A3D808AB472CF67226E_12074_240x110_61066843f0238e5e222c5605c1636587.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".