NHRed, interesting find. Mandrel solutions is a company that specializes in tube bending and selling kits. Mandrel bending is a procedure; when you bend something round it tends to simply wrinkle, which is unacceptable so mandrel bending is supporting the outside half of the bend in a machine so that you bend the tube but it stays round and doesn't wrinkle. If it wrinkled it would slow the exhaust and cause a mild obstruction. Not good. So properly bending tubing is mandrel bending it and ALL bending machines use that system. But this website is interesting in that they are one more business that has discovered the value of Aero mufflers. Good luck to them. Walk