The WSHL is designed to work with the Simpson Strong-Tie Quik Drive auto-feed screw driving system. This screw is ideal for securely fastening subfloor panels to floor joists. The Quik Drive system features non-skid teeth that provide increased stability resulting in uniform toenailing and countersink on slick surfaces. WARNING! This product can expose you to chemicals including wood dust which is known to the State of California to cause cancer. For more information go to www.P65Warnings.ca.gov -