Vertical Threaded roof outlets are available in either LM6 Aluminum Silicon casting allow to BS1490:1970 for most roof finishes or in leaded gunmetal bo Bs1400:1985 for use with lead or copper-clad roofs for connection to copper pipework. They are female parallel threaded to BS21:1985. Foamed insulation coating can be applied to both aluminium and gunmetal vertical threaded outlets for 'warm-roof' installation.