304 Stainless Steel NW flange adapters for use with circulators. Connections either terminate in M16x1, M24x1.5, or M30x1.5 male. There is no need for thread sealent or teflon tape. Connections only need to be hand tightened then given a 1/4 turn with a wrench. Compatabile with all circulator companies connections having matching female connectors.