4-1070, 4-1071, 4-1072, 4-1073, 4-1074 and new style 4-1050 outside cover lens size 3-1/2 x 4-1/2 in. Protect more expensive filter plates from pitting and scratches. Replace pitted and scratched lens immediately to protect yourself. Use plastic whenever possible for safety. Material plastic. 2 per package.