master cylinder dimensions

[car.crash]

does anyone know the dimensions of the master cylinder. i am after the piston size within the cylinder.
i need to find these out in order to know what size pistons to order for the calipers, thanks

[Sparkie]

the gtt runs a 19mm one, same as the cit AX.

[car.crash]

Thanks sparkie. One last question what size piston does the front caliper use. Thanks