High density PTFE TAPE according to MIL-T27730A, UL. Applied for all types of threaded fittings for passage of water potable and non-potable,most chemicals, oxygen, gasoline, natural gas,hydraulic and high-pressure lines.Yellow gas line PTFE tape is a high density PTFE Tape specifically used on natural gas,propane and butane lines. Pink Plumber Line Thread Seal Tape is a full density thread seal tape for used with piping in air,water,sewage,hydraulic lines and sprinkler systems. Blue Industrial Thread Seal Tape is high quality and specially for industrial pipe.Green Oxygen Thread Seal Tape is recommended for all oxygen lines. GRAY Stainless Steel anti-seize PTFE TAPE has nickel pigment colour added and recommended for all stainless steel pipe and fittings.