i have the fx39. I got it from revzilla. Same helmet as the Trekker. I wear it on my DS sometimes, mostly on my street bike though. Honestly I don't like it as much as an MX helmet with goggles (for DS/dirt duty) or old full face helmet (for streetbike duty).
It flows too much air with the vents closed (i was hoping to use it more in the cold), too loud with shield closed, catches more wind than my MX helmet when I turn my head to the side.
I mean it looks cool, but I can't say the DS style is any better functionally.
Kawasaki KLR650 - Adventure Lite
Tagged KTM250XCF-W - Rocket
Tagged KLX300 - Trail Tractor
'84 XR250R - Retro Ride
RMZ250 - Dirty
CRF80 - Kids
CRF70 - Kids