New disc brake rotor

Folks,

A bit more info on this item:

a) you have to install the studs as far as I can tell;
b) it is sbp as far as I can tell measuring from right side of the hole 2 to the middle
of hole 4
c No splines on the inside but it has two circular sections with air slots in between them..I guess that is for cooling.

Thanks
Ian.