The cwa 400 will flow 150ltrs per MINUTE, most others are rated at litres per hour. It will flow this at upto 0.8bar.

I found a lot of info here

http://mbworld.org/forums/w211-amg/411058-intercooler-pump-you-didn-t-know-about-4.html

The cwa50 and 100 are the intercooler pumps.