What You Will Receive: you will receive 4 x 3/4inch NPT Chicago fittings, 4 x silver safety locks and 4 x rubber washers, the quantity is enough to use, can meet your needsPressure Grade: the recommended maximum working pressure is under 150 psi to prolong its service lifeRustproof and Durable Material: the universal 3/4 air hose is made of carbon steel, and the surface is galvanized, to prolong the service timeInstructions for Use: each connector is equipped with a safety lock, which is applied to insert into the locking hole on the fitting to that the air hose repair end is connected correctlyWidely Application: the universal air fitting can be applied to many occasions, such as pneumatic equipment, automobile industry, air compressors and mechanical engineeringPlease note: the physical slightly color difference or difference,please do not mind, thank you!Colour:SilverMaterial:carbon steelPackage Contents:4Sets * NPT Air Hose FittingOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.