Corona has been one of the most popular IST masks and its superior fitting and comfort are the reasons behind the success. Its swivel buckle allows the diver to adjust the mask to the most desirable position. The low internal volume gives unrestricted view. 

Anti-fog lens available (M55/AF) 

Optical lenses for M55 CORONA masks are available in:

•  -1.0 to -8.0 in -0.5 decrement (also for tinted lens). Left / right lenses are interchangeable
• +1.0 to +4.0 in 0.5 increment (not available for tinted lens). Left / right lenses are interchangeable
• Left / right lenses are interchangeable for Minus and Plus lenses
• Reading lenses at the base of the mask lens for M-55 masks are available in diopter from +1.0 to +4.0 in 0.5 increment. Left/Right lenses are NOT interchangeable.