This exhaust extension allows for safe venting of exhaust fumes from an unoccupied enclosed area - this will allow your expensive unit to stay dry and secure while maintaining portability. This adapter is designed for use on stock muffler ports that are 1-1/4" (32mm) or less in diameter, weld bead diameter under 1-7/16 inch (36.5 mm) and length of less than 1-1/2 inch (38 mm) long. See pictures for further explanation. All dimensions are with the spark arrester removed. The spark arrester will have to permanently removed for this modification. The buyer will receive: a custom 1" NPT threaded weld-on exhaust stub.