Octave Key Neck parts fits many Yamaha Sax Necks.

ALL GENIUNE YAMAHA PARTS

Includes flat spring, spring screw, lever shaft/screw and pad
Flat spring screw is VERY small and requires a precision screw driver. 

Should also fit the following:

AD-AS1
YAS-01M
YAS-01MQ
YAS-100
YAS-200AD
YAS-200AD(2)
YAS-200DR
YAS-200DT
YAS-23
YAS-23S
YAS-23U
YAS-25
YAS-25L
YAS-26
YAS-26S
YAS-275
YAS-275S
YAS-280
YAS-280S
YAS-32
YAS-32(2)
YAS-32(2)E
YAS-32F
YAS-52
YAS-52E
YTS-100
YTS-200AD
YTS-200AD(2)
YTS-200AD(S/N K30000-)
YTS-23
YTS-23(S/N K30000-)
YTS-25
YTS-26
YTS-26S
YTS-275
YTS-275(S/N K30000-)
YTS-275S
YTS-280
YTS-280S
YTS-32
YTS-32E
YTS-52
YTS-52E

Yamaha Genuine Part.