Form: This specification covers a permanently mastic polysulfide compound in the form of a paste. Application: This product has been used typically for sealing or resealing integral fuel tanks designed for groove-injection type sealing for use from ?65 to +250 ??(?54 to +121 ??@ with intermittent use to 300 ??(149 ??. Classification: Sealing compounds covered by this specification are classified as follows: Class 1 - Medium viscosity@ permanently mastic@ fuel resistant@ polysulfide paste compound suitable for sealing applications with structural mismatch of 0.008 inch (0.20 mm) or less. Class 2 - High viscosity@ permanently mastic@ fuel resistant@ polysulfide paste compound suitable for sealing applications with structural mismatch of 0.015 inch (0.38 mm) or less. Normally contains glass bead filler material. Safety - Hazardous Materials: While the materials@ methods@ applications@ and processes described or referenced in this specification may involve the use of hazardous materials@ this specification does not address the hazards which may be involved in such use. It is the sole responsibility of the user to ensure familiarity with the safe and proper use of any hazardous materials and to take necessary precautionary measures to ensure the health and safety of all personnel involved.