Camera Light Seal Foam is also called a Light Seal and it is located inside the back cover of camera. It is to prevent from light leaks. Japanese camera manufactures have used this materials for anti-reflection long time. Therefore, this is best anti-reflection materials for cameras and Binoculars. It is to prevent from light leaks. Japanese camera manufactures have used this materials for anti-reflection long time. Therefore, this is best anti-reflection materials for cameras and Binoculars. Made in Japan