duct fittings T-piece /tee/ air duct type: pressed , with gasket or without size: 80mm-400mm material: galvanised steel -- duct fitting With gasket and without gasket , cross intersections.T-piece/tee/air duct/vent duct /pipe are widely used in air conditioning, airports, shipbuilding, exhibition, Coliseum ,etc. T-Piece fittings 90 degree with gasket or without gasket (duct/vent duct)