I have an Elka Stage 4 shock for 2006 - 2010 600/750. This is a 4 way so it has adjustment for high speed compression, low speed compression, rebound, ride height, and of course pre-load. Comes with a 575 spring so would suit a rider 170 - 190 pounds as it sits now. A beautifully made piece which is ready to bolt in and go. $600 shipped obo. PM me and I am happy to send pictures (I can't seem to upload them here)