Has anyone used both before? even on different cars?

When i looked at my Spec one and my old Sachs one, i noticed they look the same. on closer inspection, both Sachs PP. the difference, the 'Sachs' one is steel and the Spec one is aluminium inside (as i ordered)

Apparently the aluminium one is suppose to have more clap force, how? i'm not sure.

The other difference, different numbers on the PP itself.

I actually thought Spec made their own PP. Guess not? maybe just custom aluminium plates on their semi aluminium and custom plate and cover for the full aluminium one?

Sachs:


Spec:
http://s107.beta.photobucket.com/use...tml?sort=6&o=1