The ear straps have adjustable loops on them so you can tighten to your needs.
Each mask has an interior pocket that will hold a meltdown filter insert which is included with your purchase or you can use your own filter.
What is meltdown fabric? The melt blown process is a nonwoven manufacturing system involving direct conversion of a polymer into continuous filaments, integrated with the conversion of the filaments into a random laid nonwoven fabric. First developments in this field of technology in the industrial area started around 1945. - Science Direct
Sizing: Adults Sizing: 5.5 H x 6.5 W
These should be hand washed and hang to dry