Small = 2-5 Years
Medium = 5 Years-Teen/Small Grown-Up
These East Van Mom-made masks are now three layers thick, with the middle layer being polypropylene, as the smart folks up top have recommended. They're super comfortable, cute & sassy and come in untampered-with packaging, for that extra safety factor.
Seb's been wearing FTLOO masks exclusively since the beginning of the Strange Times. I personally love putting him in the 'over the head elastic' version, because I know that he's taking his mask off and putting it back on again multiple times throughout the day at school and the elastic stays around his neck, so the mask does too! For real, he's only lost ONE since school started back in September!