That was never an OE fitment.

What you appear to have got there is a Brembo PS series master cylinder. Much better quality than the original I might add!

AFAIK the PS series master cylinders come in 10-16mm piston sizes and I'd guess that it's probably a PS11 or PS12 on your bike? They are sold by Brembo as aftermarket master cylinders, but were also fitted as standard to several KTMs, Husqvarnas and Moto Guzzis. You should be able to find a replacement switch easy enough if you search the web for Brembo PS master cylinder. I think the switch is the same regardless of what piston size it is.

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