Rotor Button

[paperboy]

Hi All,
I picked up a new rotor button from rare spares yesterday (black one) and discovered that its completely different from the one that's on the car and it doesn't fit. (see pictures)
I'm assuming mine (red one) is a genuine holden one and the other is a bosch one. Anyone know why they are so different and where can I buy a new red one from?
Many thanks
Geoff