Lagos for comfort ESPC vinyl flooring with underlayment attached. – Harper Floors
QuietWalk 200 sq. ft. x 66 ft. x 3 ft. x 1.4mm Acoustical and Vapor Barrier Underlayment for All Vinyl Plank Flooring QW200LV - The Home Depot
STEICO 3 mm 1/8 Inch Wood Fiber Flooring Underlayment for Laminate Vinyl LVT LVP Hardwood Floor 90 SqFt Natural Sound Insulation Barrier - Amazon.com
The Right Underlayment for Vinyl Flooring Makes All the Difference - Panel Town & Floors
STAINMASTER PetProtect Bascom Park 20-mil x 7-in W x 48-in L Interlocking Luxury Vinyl Plank Flooring (18.57-sq ft/ Carton) in the Vinyl Plank department at Lowes.com