BRASS HOSE BARB RIGID MALE ADAPTER HOSE BARB 5/8" (16 mm) HOSE BARB ID X 1/4" MALE NPT ( diameter = 0.54 inch) PLEASE NOTE, 1/4" NPT MEASURES 0.540" OUTSIDE THREAD DIAMETER IN LINEAR INCHES MAX PRESSURE 150 PSI TEMPERATURE RATINGS FROM -40f THROUGH 160f