Aqua Sphere Sphera mask is one the most popular mask among freedivers.
Why freedivers like Sphera Mask?
-extremely love volume, approx 65 ml inner volume which is nearly the half of a normal freediving mask’s volume, therefore no equalization needed approx up to 25 meters (82 feet)
-extremely wide field of view thanks to the curved lenses which is a unique design
Cons: lenses scratch easily. It is equipped with plastic lenses, not tempered glass because the lenses are curved to provide 180-Degree field of view.
Freedivers find Sphera more fragile, but they say the lower price compensates these disadvantages.