Poseidon Whiteline MaskWhiteline Mask Product information 120 mm 4. 75" skirt width 150 mm 5. 9" lens width Includes mask hard case This ultra low volume, matte mask incorporates a unique, lightweight frameless design and a single lens with a slight downwards angle to provide an unprecedented field of vision combined with great comfort for most face types. The extra deep and ultra soft skirt provides a comfortable and flood resistant fit, which even works great with beards.