fit runs small [SEP] while this was lightweight and very helpful allowing air to pass freely through my mask the fit was not good whenever i spoke it moved and shifted causing me to need to touch my mask and readjust it to keep it from falling off my face i ended up taking it out and finishing up my workday without it because i no longer felt safe having to constantly touch my mask to readjust maybe for a kid with a smaller face it may fit better but for an adult the fit is too small if your needing to talk