I ordered the STOCK KX500 tank from them, and when I received it, low and behold it is half inch narrower than stock.
The middle of the tank is half inch narrower, and when you put the seat up to the tank, you REALLY notice it. The way the tank is shaped, this is a major gap, and they should have posted this on their website. *** NOT STOCK DIMENSIONS***
Further they told me that If I want, I can air poressurize it to expand it bigger! (What a load of CRAP, I have the email for doubters.)
FYI,,,, If you want a narrower tank, this is the one for you!