SLP Super Silent Muffler

I read several positive reviews on this product, and figured quieter is better-
especially when the quieter muffler is less restrictive than stock. However, when I received the product I discovered that the spark arrestor is NOT
USFS approved. It’s a nice muffler, and I’d like to run it on my 800s but I’m
concerned that I could end up with a $225 ticket for an unapproved spark arrestor. I’ve called the manufacturer as well as FMF hoping someone could recommend an approved S/A that will fit- no luck. The ID of the radiused pipe where a spark arrestor would normally go is 1-5/8". Does anyone know if the stock S/A will fit (my RZR is not here at this time to measure)? If not, any recommendations from those who may be running this setup?
By the way, the Manufacturer specifies the spark arrestor (which is located at
the junction of the cannister and outlet pipe, where it would fail the usual "stick test") is not USFS approved, but nearly every vendor who sells these things indicates (mistakenly) that it comes with a USFS approved S/A.