Permatex® Permanent strength threadlocker red and cup/core plug sealant retaining compound. Dual purpose. A permanent, high strength product that is applied to fasteners 3/8 to 1 inch size before assembly. Designed for securing parts that must withstand heavy shock, vibration or extreme chemical or environmental conditions. Also used for sealing and securing cylindrical metal assemblies. Localized heating and hand tools are required to separate parts.