have dual engine setup in very good condition risers were just done by stainless to make them semi -dry. looking for 4500

What exactly does that mean? I have never before heard someone classify their exhaust as "Semi-dry"....

Semi wet

Uses a water dump like dry but also still let's very little water mix with the exhaust. Risere are 16in from the bend and are standard bravo fitment

I got it now, so you can still run a flapper and not burn it off...???

U got it