Interesting, thanks for sharing.

> So how to know a mask is safe? Check whether the mask has a one-way breathing system, verify that one-way valves are in place both in the snorkel as well as in the orinasal mask section, and last but not least check if the orinasal mask makes a good seal on your face. If these checks are positive, then it is a good indication the mask is safe to use.

Thanks, yes my mask is properly designed with the one way valve system and small sealed breathing pocket around the mouth. I definitely appreciate that this product has a complex design to ensure safety and that a knock-off could be dangerous.