(For Fire Hose Coupling) Material: Brass or Aluminium Size: 1-1/2", 2-1/2" Thread: NST, NPSH Type: P/P, R/R, P/R Advantage: safe, fast, easy, flexible Details: Rocker Lugs(NH fire hose coupling) are sold in sets (1 Male and 1 Female per set) Aluminum Rocker Lugs are seamless and anodized. They include swivel gasket and brass expansion rings Fire hose coupling is the connector on the end of fire hose to connect or couple it with another hose or with a tap or hose appliance, such as irrigation sprinkler. It is usually made of steel, brass, stainless steel, aluminium or plastic. Used for combining water band with water band, fire hydrant, water lance and the fire-fighting truck so that they are to supply water or foam misture for putting out fire.China Fire Coupling suppliers website:http://www.camlockcouplingcn.com/hose-coupling/fire-coupling/