First the spark arrester is not the same part. And you don't really want to be buying it; unless, you are required to have it like out in extreme drought prone areas. This part even cost me $100 to purchase for my customers. I haven't sold one to date.
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The part shown by the OP is sold as part of the muffler. The muffler itself is most likely already burn out internally and rusted out too. It relatively a low cost item from Husqvarna. Even cheaper if you buying from the distributor like I do. I have multiple of these twin mufflers and the single mufflers too. The low cost makes it easy when compare some the mufflers I have to replace due major damage. I replace one a month ago that was $250 and it was the kind that I can save normally due the customer lost a huge chunk of it.
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