This mask is adult-size - even if you have a "large build" it should fit you fine - it measures 6-5/8" wide by 8-1/4" tall. It's too wide for my face; my eyes and nose don't quite line up with the cut-outs, but I can still see and breathe. It's similar in quality to what you'd find in a boxed set Halloween costume, but slightly thicker.  The elastic band is 1/4" wide and has Velcro to adjust the fit. Seems durable as it was tossed in the Amazon box loose with no bubble wrap, inflated pillows, or anything wrapped around it, along with another item, and it arrived with no scratches.