These plastic filters are ideal for blocking visible light, while transmitting near infrared wavelengths. They are made by new plastic technology material with properties that can satisfy a variety of optical and environmental. They're at half the weight of glass filters. They  are resistant to all types of chemicals and solvents (acetone, acids, alkali and alcohols). In addition to having excellent thermal characteristics, they are resistant to pits from hot sparks resulting from welding or grinding processes, The filters can also be easily drilled with high-speed carbide bits for all types of mounting