Kickport's FX Series™ Sonic Enhancement Ports produce a clearer and more focused resonant note that dramatically improves the projection of the natural tone of your drum. The result of more than three years of research and development, these patented accessories also reduce unwanted overtones, enhance resonance and deliver an incredible three-dimensional sound in all environments. Like all Kickport products, FX Series™ Sound Ports are compatible with your favorite brands, sizes, and styles of drums, heads; plus, compatibility with all of your drum microphones. This 2" insert is intended for kick drums.