Special Air Hose Connector Design: Designed to be rotatable to prevent twisting of the hose and lock the tool onto the air hose, the female connector has a valve to prevent air from escaping when changing between tools. Compatibility: 1/4 compressed air fitting accessories, compatible with pcl, vertex, airflow, etc. Suitable for pneumatic tools, automotive industry, air compressors, mechanical engineering, etc. High quality materials: Air hose connector are made of galvanized steel, durable and have resistance to rust and corrosion. Easy to install: 1/4 compressed air quick coupler make tools and airlines can be quickly connected and disconnected, quick and easy to install, just slide the clamp back and insert the connector, simple to use. Packing: 4x1/4 BSP internal thread, 4x1/4 BSP external thread, 2x1/4 BSP internal thread, 2x1/ 4 BSP thread