ORSEN Newest Version Snorkel Mask Foldable 180° Panoramic View Free Breathing Full Face Snorkeling Mask with Detachable Camera Mount, Dry Top Set Anti-fog Anti-leak for Adults & Kids

What you should know before buying a full face snorkeling mask?

What are the current problems with most snorkeling masks:
1,Size problem, the exact size is hard to select S, L or XL? it is diffcult to choose the right one.
2,Not well sealed, leaking.
3,The mask always fogs up.
4,Hard breathing

How to solve the problem?
ORSEN team has developed a...