Extends over the eyeglass to provide a comfortable cushion fortheeye. This rubber eyepiece eye protector fitsmost optical instruments with eyepiece sizes from 36mm to 43.5mm flexible, lightweight and soft rubber material.Made from Rubber with MultiFolds and Ergonomic Obliques Eye Cup, Providing AmpleFlexibility as Comfortable Cushion and Protections. Improves accuracy through quick eye positioning for proper eye relief and optical centrealignments. Preventsglares,helps focusthe mind and protects the eyes from harm.