These Vortex ZYP woodscrews are a premium quality woodscrew with tailored product features and technical advancements for use in almost any application. The recessed double countersunk head provides the screw with added strength beneath the head to reduce the likelihood of shearing, and sharp milling ribs underneath the head help with effective countersinking so there's no need to countersink the wood beforehand. Supplied in a handy site case with 610 pieces in 8 different sizes.