Welcome to the forum.
The button is not available separately from what I can see so you need to harvest one off of a complete unit. I see the whole unit on ebay for $30.
The good thing is that they used that switch assembly on a bunch of bikes.
ASSEMBLIES WHERE 37400-33E31 IS USED
1996 GSX-R750X - Handle Switch
1997 GSX-R600 - Handle Switch
1997 GSX-R750X - Handle Switch
1997 TL1000S - Handle Switch
1998 GSX-R600 - Handle Switch
1998 GSX-R750X - Handle Switch
1998 TL1000S - Handle Switch
1999 GSX-R600 - Handle Switch
1999 GSX-R750X - Handle Switch
1999 GZ250 - Handle Switch
1999 TL1000S - Handle Switch
2000 GSX-R600 - Handle Switch
2000 GSX-R750 - Handle Switch (Model Y/K1/K2)
2000 GZ250 - Handle Switch
2000 TL1000S - Handle Switch
2001 GSX-R1000 - Handle Switch
2001 GSX-R600 - Handle Switch
2001 GSX-R600Z - Handle Switch
2001 GSX-R750 - Handle Switch (Model Y/K1/K2)
2001 GZ250 - Handle Switch
2001 TL1000S - Handle Switch
2002 GSX-R1000 - Handle Switch
2002 GSX-R600 - Handle Switch
2002 GSX-R600Z - Handle Switch
2002 GSX-R750 - Handle Switch (Model Y/K1/K2)
2003 GSX-R600 - Handle Switch
2003 GSX-R600Z - Handle Switch
2003 GSX-R750 - Handle Switch (Model Y/K1/K2)
