Compression Fittings do not need any flaring, fusing or other types of tubing preparation; Available in a variety of sizes and styles; Low Cost Product Application: For use with instrumentation hydraulic and pneumatic systems. DO NOT use for gas connections of any kind.; Designed to be used with aluminum, copper and plastic tubing. Not recommended for steel tubing. Plastic tubing will require a 63PT insert and 60PT sleeve.; Recommended for pressure ratings from 0-400 PSI Tramec Sloan manufactures brass fittings in the USA! Machined at our facility in Ohio, high-quality is guaranteed. Look for TS USA stamped right into the brass!