Eaton Weatherhead 131X5 Brass CA360 Inverted Flare Brass Fitting, Plug, 5/16" Tube OD (Pack of 5) Inverted flare plug fitting for closing the end of a tube Male 1/2-20 inverted flare threads for use with 5/16" OD tubes CA360 brass for strength and resistance to corrosion Operating temperature range of -65 to +250 degrees F (-53 to +121 degrees C) Meets SAE 040109 specifications for tube fittings