3M electrical moisture block (EMB) is a is a specially formulated rubber adhesive/sealant for moisture proofing wire bundles. Resistant to salt water, corrosive chemicals and automotive fluids. Flexible over a wide temperature range. Easily installed. Flame-retardant. 3M electrical moisture block (EMB) is a self fusing, rubber based insulating adhesive/sealant designed to prevent the migration of water along harness wiring. EMB block is supplied on a release liner and offered in three standard sizes to accommodate different size wire bundles. It is compatible with typical wire insulation such as PVC, Hypalon and crosslinked polyethylene.