I just pulled the pods off of the Rat Race 836 and used them I think they are Emgo, just mesh with a fabric in between. The K&N's that were on it are toast and they don't make them any more. I tried to soften the rubber in my magic rubber solution (wintergreen oil) and the ultrasonic cleaner but still couldn't get them back on.
There aren't many good pod filters in the 44/45mm size, same size as the Honda keyhole carbs. I'm finding some at APE, I'm not sure what type they are, ebay has a lot of china products, either the Emgo ones or there are some foam oval ones. Mine are baffled on the inside to try and straighten out the flow.