BrassCraft insert are ideal for use with nylon and plastic hose. Not recommended for use with steel tubing. Brass construction O.D. Tube Designed for use with aluminum and copper tubing. Not recommended for steel tubing Designed for use with potable and non-potable water, instrumentation, hydraulic and pneumatic systems For use with nylon and plastic hose Rough Brass May be used in both indoors and outdoors. Temperature rating: 40° to 180° F Pressure rating: 125 PSI maximum