The Forney 75305 Industrial/Milton Style 1/4-Inch X 1/4-Inch Plug and Coupler Set is steel construction. Forney airline accessories are intended for use on compressed air lines only. Forney Industries is one of Americas longest operating family-owned metal working product companies. Founded in 1932, Forney offers more than 5, 000 products for the hardware, automotive, farm and ranch and do-it-yourself markets. for more information, visit www. forneyind. If you've got metal working questions, we've got answers. Were committed to your success regardless of location size or needs. Please contact our team at www. customerserviceatforneyind. Industrial/Milton Style 1/4-Inch (6. 35mm) X 1/4-Inch (6. 35mm) Plug and Coupler Set. Max working pressure is 300 PSI. Claims for must be made within 90 days of the date of purchase. Proof of purchase required. This does not cover any product that has been subject to misuse, neglect, negligence or accident, or that has been used in any way contrary to the purpose intended.