S&S Off Road Division Muffler Inserts For Power Tune XTO Exhaust The Muffler Inserts developed by S&S are built to enhance the Power Tune XTO Exhausts. They offer the flexibility to modulate both performance output and noise levels, tailoring the exhaust system to meet individual preferences. Features: Easy to install, simply remove the end cap and replace 304 stainless construction 1.375- 2dB quieter than standard 1.50- standard insert 1.625- 2dB louder than standard 1.75- 4dB louder than standard 1.875- 6dB louder than standard 2.00- 8dB louder than standard 2.25- 10db louder than standard