Can be used in conjunction with the Temperature Gauge (p/n 174 or p/n 6054) for monitoring furnace supply water temperature, or may be used instead of Nipple (p/n 533) and 90° Street Elbow (p/n 274) on supply and/or return bung. Brass Offset Tee, 4", 3/4" MPT x 1/2" MPT x 3/4" MPT.