... for extreme resistance to abrasion and corrosion, IP68.3.High quality tempered glass with excellent light transmittance.4.Comply with ... Ex, ib, IIC, T4, IEC60079-11, EN60079-11.5.Designed with advanced Optical Principles, making visual distance up to ... icationsMine, petroleum and petrochemical, aircraft, mi l itary, outdoors, indoors, portable-emergency kits.Working temperature: -20°C to +40°C