PR 1773 CLASS B IS TWO-PART MANGAMESE DIOXIDE CURED, POLYSULFIDE-BASED SEALANT CHARACTERIZED BY LOW PROPERTIES. THE MIXED COMPOUND IS A THIXOTROPIC PASTE. IT DOES NOT FLOW FROM VERTICAL OR OVERHEAD SURFACES. PR 1773 CLASS B ACTS AS AN EFFECTIVE BARRIER AGAINST THE COMMON CAUSES OF CORROSION ON ALUMINUM ALLOYS OR BETWEEN DISSIMILAR METALS. IT HAS A SERVICE TEMPERATURE RANGE FROM -54°C TO 121°C (-65°F TO 249,8°F), WITH INTERMITTENT EXCURSIONS UP TO 149°C (300,2°F).