Study finds all N95 masks effective for reducing an ill person's danger to others, especially duckbill masks
https://www.thelancet.com/journals/ebiom/article/PIIS2352-3964(24)00192-0/fulltext
"All masks and respirators significantly reduced exhaled viral load, without fit tests or training. A duckbill N95 reduced exhaled viral load by 98% (95% CI: 97%–99%), and significantly outperformed a KN95 (p < 0.001) as well as cloth and surgical masks. Cloth masks outperformed a surgical mask (p = 0.027) and the tested KN95 (p = 0.014)."