This is the standard industrial quick disconnect used by carpet cleaners on many of the mini spotter and on machines that use a less than 3 gallon tank size. Uses 1/8" female pipe threads. Series B (brass). Spring loaded plug in tip keeps water from dripping out of end while you set up or wrap up your hoses. Please note that 1/8" pipe thread is 3/8" diameter on a ruler 1/8" QD is 1/2" across on QD side. 1/8"-27 NPTF Female Compare to current of past OEM associations: PMF QD75 Esteam 580-100 PAF04 Powrflite PC7 Eaton Hansen B1H11 Brass ISO-B Interchange Hydraulic Fitting, Socket with Valve UNSPSC 27121700 ASIN B00F4JA19W Karcher 86218790 Windsor 8.621-879.0