GAS/TFE Tape, Yellow PTFE Tape For Gas Line, 1/2-Inch x 260-Inch Manufactured especially for natural gas, propane, butane, water, oil and chemical lines. Heavier than white tape with density of 1.35 - 1.50 grams/cubic centimeters, 4 mils thick. Complies with MIL-T-22230A (ASG), UL 31 RO, AGA 3226 and CAN/ULC-S642. A high density product that resists tearing and stretching for easy, efficient application Provides a clean, positive seal on threaded connections