4412G Extreme Sealing Tape 4412G Gray 80 mil, 2 in x 18 yd, 6 rolls per case. 3M™ Extreme Sealing Tape 4412G is a gray, highly conformable, single-sided, pressure sensitive acrylic adhesive tape with a high performance ionomer backing. It is an ideal solution for creating a water tight seal. It conforms over fasteners, seams, joints, holes and gaps to ensure a long-lasting seal on a variety of substrates.