Content: 3pcs 6mm One-way Flow Pneumatic Check Valve, Pluggable Air Hose Connector for Air Compressor. [Dual Use]: Pneumatic connectors are used to connect polyethylene pipes, nylon and PU, air hoses and pneumatic tools, and are widely used in automation equipment industries such as machinery, electronics, automobiles and packaging. [Working environment] : 0-8 bar. Operating temperature : 0-60. Applicable pipe materials: PU/nylon/PE. Authentic These accessories are made of high quality plastic, durable and airtight, suitable for long term use. With integrated stainless steel locking claws and NBR O-rings, you'll never worry about the tube falling out again. It has high pressure resistance and can withstand strong pressure without tripping, so there is no need to trip. Easy to install: no additional gaskets are needed, it Just attach it to the pipe with one click and they stick firmly. Oval release rings on both ends make disassembly easy and require no additional tools. In addition, these accessories are flexible and space-saving and can rotate freely 360 degrees.