http://www.xt660.com/showthread.php?...ht=foam+filter

I followed supamanaint's lead and ordered the XTX filter...but was a little concerned that this filter is listed in their road bike section. So, I went a step further and contacted Uni Filter. These guy's were extremely helpful and despite having MADE the XTX filter, were happy to produce a filter for my XTR. Straight from the horses mouth (Mark @ Uni Filter). The foam used in the XTX filter is different and not suited to off-road use. However, they simply make one up with foam suited to the application. Cost = $41 + $7 postage here in NSW Australia. I've ordered (2) for ease of service and given the cost.

The DNA's are great, but... for strictly road use. I took a short detour on the way home yesterday. No more than 10 km's of dirt. Got caught up behind a truck (murphy's law) and by the time I arrived home the stage 2 was noticeably affected.

Uni Filter also strip and foam a filter. So, I plan on forwarding the stage 2 for them to have a look. Only problem is I paid around $100 for the stage 2 and to tear it up hurts.