Push to connect fittings type: 1/4'', 5/16'', 3/8'', 1/2'', suitable for 6mm 8mm 10mm 12mm OD tube. Material - Made of quality PU and plastic. High pressure resistance, long service life, can withstand strong pressure without tripping. Great for long-term use. Practical design: space saving, rotating at 360 degree, the release rings adopt the elliptical design, which can be removed easily. No additional sealing is needed, just a simple push to ensure a secure connection. Application: It is widely applied in automatic production equipment of industries like machinery, electronics, automobile, packaging. What you get: 40 pieces of fittings, including 10 for 1/4 inch fittings, 10 for 5/16 inch, 10 for 3/8 inch and 10 for 1/2 inch, meeting your different needs.