Yamaha, YAS-23 Saxophone (and others), Needle Spring Set, 1 Set.  See my related items - flat spring kit Item ID# 274350073680 & flat spring screw kit Item ID# 274350082438.
Fits:
AD-AS1 2002 〜2004
YAS-01M 2004〜2006
YAS-01MQ 2004〜2006
YAS-100 1994〜2002
YAS-200AD 2004〜2011
YAS-23 1979〜1992
YAS-23S 1980〜2011
YAS-23U 1986〜2011