Ordered from Home Depot and used under a vinyl flooring for sound proofing. I'm glad we used; wish I had used on other installations, even though the flooring comes with its own backing. Originally cost $160.
Robert's AirGuard 630 sq. ft. 40 in. x 189 ft. x 2 mm 5-in-1 Underlayment with Microban for Laminate and Engineered Wood Floors
-more than half the roll left.
$50 obo.