The material is designed for use as an access door sealant or in the fabrication of form-in-place (FIP) Gaskets. It can be used to protect electrical wires, terminals and equipment against fuel, moisture, dirt and short circuits. PR-1428 Class B is a two part, manganes dioxide cured, polysulfide compound. The uncured material is a low sag, thixotropic paste suitable for application by extrusion gun or spatula. It cures at room temperature to form a removable seal to common aircraft substrates.