Intertape 4237 high tensile strength glass filaments and conformable PET film coating with an aggressive adhesive for a variety of heavy-duty insulating, banding and holding applications. 1 Mil polyester film provides puncture, edge tear and abrasion resistance. - Specially designed and intended for use in oil-filled transformers. Once thermoset, the acrylic adhesive offers superior resistance to chemicals, solvents and aging in addition to excellent dielectric strength and insulation resistance.