Good luck on finding one.
I've checked a number of different company catalogs which show the diameters and height of their filters and have yet to find one that would be comparable in size.
There are several that are either smaller in diameter or shorter but IMO, although the smaller filters might work on a 350cc bike, those would not allow the airflow the big 500cc engine needs.
Then their is the K&N filter. Some like them. I don't.
Mine reduced the fuel economy and power on my 2011 G5. That's why I went back to using a factory filter.
For those interested, the OEM filter is 4 5/8" (4.62", 117mm) outside diameter, 3" (3.0", 76mm) inside diameter and 3" (3.0", 76mm) tall from sealing surface to sealing surface.
The airflow on the filter for the B, C and G model RE's is from the inside towards the outside. If an attempt to blow the dirt out of the filter is being made by using compressed air, blow from the outside, thru the filter material towards the inside.
These filters cannot be washed to clean them. Doing so will destroy the paper filter element.