WINGKIND high quality cushions are made of Healthy and harmless rubber.<br> They are designed to prevent teeth marks from mouthpiece, keep teeth firmly on the mouthpiece without slipping. <br> It can be easily cut to fit the size of any mouthpiece. You can also put it on ligature area to prevent ligature scratching & slipping, Increase mouthpiece circumference to accommodate oversized ligature. <br><br> Note: <br> PLEASE clean the mouthpiece well using the alcohol wipes and allow it to dry before installing the cushion. Position them carefully, once they are on the mouthpiece, they are on and can't be repositioned.