Four densities to seal all common threaded connections. Made with 100% Virgin PTFE. Can be used on oxygen. UL® Listed thread sealant 561R (except Standard Density Zip® Tape). Meets Mil Spec MIL-T-27730A (except Standard Density Zip® Tape). Temperature Range: -400°F to 500°F (-240°C to 260°C). Pressure Range: To 10,000 psi. Thred Tape HD (High-Density PTFE Tape) Thred Tape MD (Medium-Density PTFE Tape) Thred Tape SD (Standard-Density PTFE Tape)