BrassCraft compression adaptor is machined from brass. Compression fittings are ideal for use in plumbing, instrumentation, hydraulic and pneumatic systems (gasoline, grease, oil, potable and non-potable water, vacuum and air lines). Can be used to install copper, aluminum, or plastic tubing. Not recommended for use with steel tubing. Brass construction provides strength, durability and longer-lasting performance Designed for use with aluminum, copper, and plastic tubing. Not intended for use with steel tubing Designed for use with potable and non-potable water, instrumentation, hydraulic, and pneumatic systems Plastic and PEX tubing installations require sleeves and/or inserts. Check installation instructions for exact requirements Rough Brass May be used in both indoors and outdoors. Temperature rating: -65° to 250° F at maximum operating pressures Working pressure: 200 psi