3M™ Urethane Foam Tape 4104 white, 6.4mm thick, High density open cell foam, acrylic adhesive one side 3M™ Urethane Foam Tape 4314, acrylic adhesive protected by a 0.08mm thick tan, silicone treated paper liner. Very soft, conformable, low density foam which can help seal out air, dust and light when compressed 50 percent.