Maintain and repair metric pneumatic systems efficiently with the 110-Piece Metric Push-to-Connect Fitting Kit, a high-volume assortment of straight union connectors.Designed for industrial automation, robotics, and workshop air lines, this kit provides a complete solution for connecting or extending tubing with outer diameters ranging from 4 mm to 12 mm. The straightforward push-in design eliminates the need for clamps or glue, allowing for instant, leak-free connections in seconds—perfect for emergency repairs on production lines or setting up complex pneumatic logic circuits.Constructed from high-strength PBT plastic with internal stainless steel locking claws, these fittings offer excellent resistance to aging, corrosion, and pressure up to 145 psi. The simplified union straight body allows for maximum airflow efficiency and minimal pressure drop. Whether you are servicing 3D printers, air suspension systems, or CNC machinery, this comprehensive metric kit ensures you always have the correct size on hand to keep your equipment running smoothly.