These lenses' superior oxygen supply is a result of the silicone hydrogels, ultra-porous materials used in their construction, which also happen to improve eye health. Avira medical contact lenses are highly effective in protecting against UV rays and have a superior quality. Six monthly-use contact lenses are included in each box. Sold as: silicon hydrogel box lens material 46% Water Content; Oxygen 27 permeability 14.2 mm in diameter; 8.5(-)/8.4(+) mm for the base curve Producer: Cooper Vision USA of origin