S.W.A.T. Medium Duty Moisture-Resistant Laminate Underlayment is a premium 200 sqft. underlayment choice that is not only moisture-resistant, but also virtually sound proof! S.W.A.T. Medium Duty Moisture-Resistant Laminate Underlayment is silent, water-resistant and tough, with an IIC Rating of 73, and an STC Rating of 72.