||OK, I agree the Outerwears Pre-Filters are pricey, but I really think they're worth it.
I've been running it on my RC8 for about three gallons, and I think I can say that:
- it extends the time between filter service/cleaning;
- it protects the filter foam to get soaked if you hit a puddle in a wet track (believe me: here in Rio de Janeiro it's rainning a LOT lately);
- it is easy to clean: just wash it down with dishwashing liquid, let it dry, and use again!
The downside is the price, really. If they had a 5 bucks price tag, I'd grab at least 10 of these things!