There IS a SPARK ARRESTOR being made to fit this right now, just so you know. It will be available seperatley, since not everyone may want it.
The easiest 2 hp gain you can get for your KTM 390 adventure. Just remove your end cap and install this one. No more exhaust restrictions. No ecu or fueling changes needed. It's about 1 db louder than stock but sounds like a bike now and accelerates so much better. Runs cooler as well. Any big money spent on an aftermarket slip on is a true waste of money. Weighs 5 oz less than stock.