These fittings are recommended for use with Polyethylene, Nylon, and Polyurethane (Shore A 98) tubing. Male pipe ends on tees and elbows are swivel style to allow for easy orientation during installation and Teflon® thread sealant is pre-applied for fast installation. These fittings are not approved for use with G1212 Air Brake tubing. For truck and trailer applications, please use the G7000P series air brake push-to-connect fittings.