steve, i have to say you know your fuel systems. i have not had as much experience as you with these systems, at least the extent of the intense diagnosis you likely have done. to be completely honest i searched everywhere and all my suppliers that sell this part, even bosch call them dampners. the only variant is mercedes, i know i appreciate you taking time to explain and describe their function. i knew mercedes were lacking in their description, but not to that extent, we all learn something new everyday,if you ever need any mercedes technical literature let me know, i would gladly send some your way. Ray