The 3M foil tape 3340 is ideal for sealing rigid fiberglass duct boards and flexible air duct systems. Our tape meets requirements for UL 181 A-P and UL 181 B-FX listings as a measure of reliability and quality standards. Our 3M foil tape 3340 is constructed using a 2 mil aluminum foil backing with a strong, pressure sensitive acrylic adhesive for long term adhesion, along with an easy releasing poly coated kraft paper liner to protect the adhesive and keep the tape ready for use. The highly engineered aggressive acrylic adhesive performs in both cold and hot temperature conditions. When sealing ducts and other surfaces for heating, ventilation and air conditioning systems, it's essential to have a strong, long lasting foil tape that can stand up well to hot and cold temperatures. The 3M foil tape 3340 has the combination of a foil backing and acrylic adhesive that gives our tape a superb operational temperature range of -40 deg F (-40 deg C) to 300 deg F (149 deg C). The benefits don't end there; the foil backing also serves as an excellent barrier against moisture, dust and many chemicals - making it strong, durable and long lasting. The very low moisture vapor transmission rate makes the tape a good sealant and the acrylic adhesive supplies superior temperature and UV resistance to give you a strong, lasting and reliable bond. 3M foil tape 3340 is used in a variety of applications across a number of industries, including - transportation, specialty vehicle, metal working construction, automotive, military and government, general industrial, MRO, electronics and aerospace.