This Quality Scuba Diving Mask is a fantastic state of the art mask which is ideal for comfort and performance! Good for scuba diving and/or snorkeling. Special tube and seal system automatically equalizes ear pressure as diver exhales into mask Prevents pressure-induced ear ache (barotrauma) Enhanced underwater hearing and sense of direction Watertight ear cups keep water out to keep ears warm and prevent infection Optical prescription lens option available (RX007) Please note there will be an additional 2 to 3 days processing time for most RX lenses Returns are not accepted for used lens. Only unused lens are eligible for return with store credit.