I have been using a KTM OEM sock filter for the year I have had my beast in Cambodia. See video clip:
This method works but is not ideal. The filter stores in my tank bag in double layer ziplock bags. Gas fumes still permeate the plastic and stink up the inside of my tank bag.
I have to handle the sock which puts fuel on my hand. Oh my, will this carcinogenic contamination give me cancer? According to the state of California it will and needs a warning sticker. The number one cause of death for missionaries like me worldwide is not cancer, malaria, dengue, insurgents with AK47s', or snake bite. #1 is motorcycle crash fatality. So I am not worried about the gas.
I like the convenience and cool looks of Craig's new filter/caps, and I got tired of my stuff in the tank bag smelling like Shell Oil. You can see CJ's product offer if you like at: