I'm petite, so the child size mask is just the right for covering my nose, mouth, and chin. At first my glasses fogged up when I wore my mask on my commute to work, but eventually I was able to use my mask comfortably (No fogged up glasses and the mask fit securely). After lunch break I wasn't able to adjust my mask as well as I did at home and I felt like the mask was slipping off my nose (Though sometimes it wasn't). I do appreciate how the mask's wraparound top band allows me to untie the bottom, take sips of coffee from my mug, then simply tie it back on throughout the day.