Excellent for fastening underlayment to wood, the MTH Wood Screw from Simpson Strong-Tie makes smoother work of underlayment-to-subfloor installations. This particular screw (Item #MTH114S) is sized #7 x 1-1/4", with a #2 square drive. The screw features high/low threads and a trim head with nibs. This unique threading prevents squeaks and pullouts, while the trim head allows for a flush surface. MTH underlayment screw are compatible with the Quik Drive PRO200 Drywall System and the PRO200S Multi-Purpose System.