Wedge sound-boosters are designed to work with Wedge mouthpieces, and are not compatible with other brands.
The sound-boosters for Wedge mouthpieces is a brass collar that slips over the base of the mouthpiece just below the cup and locks on with a small nylon tipped set screw. The collar makes plastic mouthpieces sound brighter and adds core to the sound while maintaining the feel of the plastic rim and the extreme responsiveness of plastic to soft articulation. It also makes attacks more secure, and improves stability and slotting significantly. For a darker sound you can just slip off the collar.
Sound-boosters can also be added to brass mouthpieces in order to add core and stability to the sound, and to reduce brighter overtones.
5/64th hex key included. Finish options are brushed raw brass or brushed silver plate.