The Cressi A1 mask is a popular scuba diving mask that comes pre-treated with anti-fog technology, making it ready to use right out of the box. The mask features a single lens made of tempered glass that provides a wider field of vision than a double lens mask. The lens is shaped like an inverted teardrop, which increases downward visibility. The A1 also offers two different lens options, clear or yellow. The yellow lens increases the vibrancy of color underwater and protects against UV. The mask is designed as an attractive, low-profile dive mask and is available in various colors.