This connector fitting is a short pipe with threads on the inside. The threads are 1/2 inch. This female thread fitting is used to connect the Sparge Arm to the hot water source. You will need this if you use A Gott cooler or any lid that is one inch +/- thick. The inside hole in the lid needs to be small enough so the fitting will not pass through the hole and the top layer needs to be big enough to let the fitting pass. Use our female thread fitting with a ctb 1/2X3/8 fitting called thread barb fitting. The thread barb fitting screws into the top end of the female thread fitting that connects to the sparge arm. The barb end receives the 3/8 inch tubing from the water source or hot liquor tank. If buy a sparge arm make sure the mash tun inside diameter matches the length of the sparge.