Seen a few of these around, I'd much prefer them over electric and fully manual (get-under-the-car-and-unscrew-a-few-wingnuts) cutouts because electric ones are only supposed to be opened and closed at idle, and I'd rather pull a cable or move a lever rather than shut the car off, let it cool, get underneath and screw with some fasteners.
The only ones I see are from Mr. Gasket, are 2", and are cast iron. I don't see how it would be possible to fasten this to a steel exhaust system. Can you weld cast iron to steel? Would you use a silicone coupler?
Thanks all.