probably loose packing material and crap sound for $40>>2.5 inlet and 3.5 out and no y pipe nor a 3 inch straight pipe under axel!! Go to a muffler shop and see what they charge you to do the bends with ss304 material and y pipe.... ....my muffler is a 3 inch inlet with dual 4 inch dia out with custom tight packing!!! and comes with y pipe and straight pipe pre bent and ready install all ss 304 material for $450~! ! A little different my young friend!