No need to keep on disconnecting an air tool to hook up a blow gun. Never gets lost or misplaced. Small, compact and easy to use. Fits permanently between air hose and coupler. Precision machined from aircraft aluminum. Air stream nozzle has a natural angle for easy use. Lightweight and durable. Available with OSHA or rubber nozzle. 1/4" NPT Female x 1/4" NPT Female.