TheAcousta-Fil Boa is designed differently to the traditional silencer wadding where you fill the desired amount, it expands to fill the space once subject to ambient heat. This latest 'Boa' version of the exhaust packing is supplied in a long length similar to a feather boa (hence the name) which makes it even more versatile than the sheet type as it allows oval or intricately shaped silencers / cans to be filled more effectively.
The boa only needs to be loosely wrapped or packed into a silencer as it expands to fill the voids when subjected to heat from the exhaust gasses, ensuring optimum sound absorption.