Tri-PLY Underlayment - Home Depot5 mm, 1/4 in., 4 ft. x 4 ft. Underlayment Plywood - This item is a hardwood and is least affected by humidity and 1/5 in. x 4 ft. x 8 ft. Hardwood Plywood Underlayment SpecialtyThe surface of these panels, straight from Home Depot, is of such high quality that I easily get a tight seal whereever it's needed. Use a fine toothed plywood blade 
T&G Underlayment Plywood (Scant Face) - Home DepotThis product combines sub floor and underlay into a single powerful panel for use under carpet and pad, vinyl 1/4 in. x 4 ft. x 4 ft. Underlayment - Home Depot5.5 mm,1/4 in., 4 ft. x 4 ft. Underlayment Plywood - Made of durable hardwood plywood. Ideal for high Underlayment - Home Depotx 4 ft. x 8 ft.; Actual: 0.175 in. x 48 in. x 96 in.) 5.2mm - Sande Plywood (1/ 1/4 in. x 8 ft. x 4 ft. Lauan Plywood-466811 - The Home DepotEvery piece meets the highest grading standards for strength and appearance. This plywood is extremely smooth and hard which is perfect for finishing with Underlayment - The Home DepotUnderlayment plywood features a minimum .25mm face veneer, 3 plies of approximately 1.6mm thick poplar core material, and a back veneer of .15mm to 1/5 in. x 4 ft. x 8 ft. Hardwood Plywood Underlayment SpecialtyApproved for use as an underlayment for carpeting, hardwood and vinyl floor coverings. (Installation instructions must be followed).