Perhaps they forgot to put it in. It was included in my product.I've been running the Guglatech air filters on my 18 ATAS for a few thousand miles now. I ordered them last year and just got around to installing them when I did fuel tank maintenance, cleaning and installing the Guglatech fuel sock on the fuel pump. I don't have any issues running oiled gauze or foam filters on motorcycles, on cars I usually just run OE or equivalent paper filters.
One issue with my order of air filters from Guglatech is they did not include the foam filter gaskets so I had to make my own and I used some narrow adhesive backed foam I had on hand. I've been meaning to contact Guglatech about this and also the fuel tank filler sock issue I have with the ATAS - the filler neck sock disrupts the fuel level sensor float so the fuel gauge is inaccurate and won't show a full tank and sometimes would get stuck. In experimenting I had to pull the sock about a third of the way out of the filler neck for the float to work properly. So I removed the filler sock from the tank because I require an accurate fuel gauge and it was damaged in the process due to the sharp metal on the underside of the filler neck despite being brand new. I don't know if this in ATAS specific problem with the larger fuel tank but I wouldn't recommend the Guglatech filler sock if you want an accurate fuel gauge.
On my ATAS, I don't find the air filter replacement terribly difficult once you familiarize yourself with the process. With the ATAS light bar, I drape a large microfiber towel over the light bar and am able to slide the side panels off without scuffing them.
I'll be removing the fuel tank again soon to install the aftermarket fuel pump and have my injectors cleaned/rebuilt so will take a look at the Guglatech filters again.
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OE Honda filters, still very clean
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Airbox looking good
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Guglatech air filter
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Can see the foam material I had to use for the filter gasket since was not supplied from Guglatech. I had to clean the plastic filter housing well in order for the adhesive on the foam to adhere to the filter housing.
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I went back and did a second layer of foam to ensure good sealing, not shown here.
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