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
Best underlay for laminate flooring on concrete is foam
ROBERTS 100 sq. ft. Roll of Serenity Foam Wood & Laminate Underlayment 70-010 - The Home Depot
Laminate vs. Vinyl Flooring: How to Choose | The Family Handyman