Tru-Blu, 1.75 OZ, Vibration Resistant Pipe Thread Sealant, For High Vibration Environments Such As Refrigeration & Industrial Applications, Designed For Sealing Vibration Prone NPT Connections, Recommended For Galvanized Steel, Iron, Brass, Copper, Aluminum, Stainless Steel, PVC, Polyethylene & Reinforced Fiberglass.