 HOUSTON, Aug. 19, 2021 PRNewswire -- Mattress Firm , the nations largest mattress specialty retailer, today announced that it has signed a multi-year extension through 2025 to its current supply agreement with Tempur Sealy International, Inc. NYSE: TPX. The news highlights Mattress Firms commitment to providing customers with an expertly curated collection of quality mattresses from the best brands. 