Fixture Mounting Stems - 18In. (1/4 Npsm Thd. Stems, 1/2 Dia. Overall). All Stems Made Of Corrosion Resistant Aluminum Alloy (Except Br And Bbr) With Baked Thermoset Powder Coating To Match Fixtures. Used With: In-Ground Support Stakes (Low Voltage Only) And Surface Mounting Flange (Low Or Line Voltage)