A DB (decibel) killer is a muffler or an insert that can be installed in the exhaust system of a motorcycle, scooter or ATV to reduce the noise level. It works by absorbing and dampening the sound waves produced by the exhaust gases as they exit the engine.
Typically, a DB killer is made of a material that is designed to dampen sound waves, such as fiberglass, metal, or a combination of materials. The sound waves are reflected and absorbed by the material, reducing the volume of the exhaust noise. The shape and size of the DB killer also play a role in its effectiveness. For example, a longer and thicker muffler will have a greater sound-damping effect than a shorter, narrower muffler.
DB killers can be removed or replaced if desired, allowing the rider to customize the sound of their exhaust system. However, it is important to note that removing a DB killer may cause the exhaust system to exceed the legal noise limits in some areas, so it is important to be aware of local regulations before making any modifications.