FloorComfort 4-ft W x 25-ft L x 5 T Premium Foam Moisture Resistant Flooring Underlayment (100-sq ft / (Fan fold) in the Flooring Underlayment department at Lowes.com
Dekorman Laminate Flooring White Foam Underlayment 2 mm Thick x 3.3 ft. W x 91.44 ft. L (300 sq. ft. / Roll) 3WF - The Home Depot