The Secoh SLL-20 is no longer being produced.
This is a bit annoying since our tests were done with these pumps of course. This summer we should have new results with current models.
Finding a SLL-20 from the current members is a long shot, as these are rare everywhere. If you really want this pump, my advice would be to check Ebay (I already checked Ebay Kleinanzeigen, there are none sadly). Maybe you can find one elsewhere in Europe?
A more realistic approach would be to look for a Secoh JDK-30. There are more suitable pumps but we have yet to test these. Others have used them and have gotten good results.