The AMS 3276 specification covers a two-part, low-density polythioether sealing compound designed for integral fuel tanks and fuselage applications where weight savings and rapid curing are essential. Unlike traditional polysulfides, its polythioether chemistry provides superior resistance to aviation fuel and a broader operating temperature range, typically from -65°F to 320°F (-54°C to 160°C). It is categorized into Type 1 (requires an adhesion promoter) and Type 2 (self-adhering).