Mueller 3/4 in. MIP X 1/2 in. D Sweat Galvanized Brass/Copper/Steel Dielectric Union

Dielectric unions are used to join pipes made from dissimilar metals to avoid electrolysis, which leads to corrosion and pipe failure. This union is made from galvanized steel and lead-free brass. Plumbing codes in all states require the use of dielectric unions when connecting dissimilar metals.