Came across this article and was wondering about what double way shock effect absorbers are and Googled it (still haven't found anything about how it works or what it is).
One of the results that came up had text that was VERY similar to what was written.
SG Carmart Article: http://www.sgcarmart.com/news/writeup.php?AID=120 (see 1, 2, & 3)
The Google result: http://www.shibumiparts.com/ingles/amortiguadores.html