No need to keep disconnecting an air tool to hook up a blow gun. Fits permanently between air hose and coupler. Small, compact and easy to use. Machined from aircraft aluminum, lightweight and durable. Air stream nozzle has a natural angle for easy use. Nozzle meets OSHA requirements of special relief hole in nozzle which limits pressure to 30 PSI when dead ended in an air line of 150 PSI or less. 1/4" NPT Female x 1/4" NPT Female