Replaces Part Numbers: 490547 496106 496106s 692038 35-027 Lo-Tone muffler Compatible with BS 6 HP Quantum Engines or 625-675 Series Engines and 4-1/2 & 5 HP Quantum models and Toro Models Lo-Tone muffler means a device used to reduce the noise of a machine, mitigating the noise of the machine and making it quiet while it is working. Ensure that the Lo-Tone muffler is effective in reducing noise by periodically inspecting for cracks or corrosion on the Lo-Tone muffler to determine if it needs to be replaced. In addition, factors such as increased power and resistance, temperature differences, etc. May cause the Lo-Tone muffler to fail. Therefore, it is essential that the Lo-Tone muffler be inspected and replaced on a regular basis to ensure the effectiveness of the Lo-Tone muffler.