The 12mm seal is better suited for automatics.  You really want the 10mm
for standard transmission setups.  Nowhere does it say this.

Mike

On 6/14/2013 11:20 PM, Karl Wolz wrote:
> Less substantial, but to my understanding, a better fit.  All I really know is that I used two of the thicker ones and both leaked.  The thinner one has now been in for several years, with no puddles.
>