Lens Protective windows are recommended for shielding expensive optics such as focussing lenses and F-theta lenses from splatter and debris during laser processing. Laser SOS provides a comprehensive range of retrofit protective windows. These windows are available in a range of glass materials such as BK7, fused quartz and borosilicate and are available with or without anti-reflective coating. Welcome to visit our official website : http://www.optics-glass.com