... from Φ1.0mm to Φ250mm clear aperture are available.Besides round, sapphire windows at shape of recangular, wedge, step windows ... Worldhawk offers standard and high precision optical glass windows in round, rectangular and custom shape and size with different optical glasses ... Germany and Europe , Rheinland Group (TÜV Rheinland Group) has over 125 years of experience in this field , has established more ...