CALI Complete 26-ft x 3.85-ft x 1.5-mm Premium Cushion Flooring Underlayment (100-sq ft /Fan fold) in the Flooring Underlayment department at Lowes.com
PRODURA 200sqft 3mm Thick 3-in-1 Advanced Thermal / Acoustics Plus Foam UNDERLAYMENT with self-Sealing Lip and Tape - Laminate, Vinyl, WPC, SPC, Bamboo, Engineered, and Solid Hardwood Floor - Amazon.com