It's not at all as comfortable as other frameless masks such as the Cressi F1 mask. We think Hollis have tried out to reinforce rigidity on the mask for sturdiness and safety by strengthening the skirt material meaning it could possibly pinch and dig if the mask just isn't a https://mask-i-109526.sharebyblog.com/28235577/m3-gas-mask-history-for-dummies