The 4 mm ULTRA Sinuscopes are powerful rigid endoscopes for sinus surgery. Those sinusscopes have an outer diameter of 4 mm and an approximate working length of 177 mm. They also come in a full complement in direction of view (0°, 30°, 45° and 70°) as well as traditional and reversed light post options. Full Complement in Direction of View 0°, 30°, 45° and 70°. ED Glass Lenses – Razor-Sharp Images High contrast at high spatial frequencies. Compatibility Mechanical compatibility to current generations of camera heads and light guide cables by Olympus and other manufacturers that correspond to DIN 58105. Eco-Friendly / Fully Autoclavable Reduced waste due to full reusability of the sinuscopes.