Yanagisawa YANY BooStar Yana/Selmer GP

I bought the BooStar because the default screw on my Yanagisawa tenor was a little too small for my fingers. This replacement makes it much more comfortable. As for the claim that it "boosts" your tone, well... I cannot make any bullet-proof claim, however my impression (for what it's worth) is that it achieves a slight improvement in tone stability. Thus, not a boost or a tonal change but, rather, maybe a little help to tone control.