Merco Tape M77 Threadmaster PTFE Premium Full Density Thread Seal Tape, 1296" Length, 3-1/2 mil Thick, 1/2" Width, White Threadmaster M 77 premium thread seal tape is a full 1.55g/cmc density, USA made product made of PTFE used for applications requiring sealing properties of a premium grade thread sealant Mil Spec T-27730A grade & current Mil Spec A-A-58092 USA made threadseal tape, intended to be used for general purpose sealing of pipe threads Maintenance free, full density, non-toxic and non-flammable, chemically inert, breaks clean Meets mil spec T-277030A & current mil spec A-A-58092 Measures 3-1/2 mil thick by 1296" length by 1/2" width by 1.55 grams per cubic centimeter denisty