Doepfer

i am sorry about being a newbie but what email address is (keyboards@...)? is that 
keyboards@doepfer.com?
also i have two 6HU frames. one has a black heat sink looking thingamajig pluged in the first 
slot on the top bus. the other one doesn't. what is this thingamajig and why does only one of 
my racks have it?

thanks agian for the help.

nate