The FastenMaster Collated Cortex Hidden Fastening System is the best way to hide fasteners on stairs, perimeter boards and more. Cortex offers a strong connection between the deck board and joist, hiding fasteners across the entire deck. Cortex plugs are made with the same material as leading deck boards, meaning you can achieve a perfect, seamless finish across your whole deck. Once installed, Cortex plugs become a part of your deck, expanding and contracting along with the boards around them-guaranteeing their strength for the lifetime of the project. Featuring a TORX ttap drive system and a high-strength setting tool, Cortex screws are easy to install and optimized for use by PRO contractors. Cortex plugs come pre-aligned on collated strips, enabling you to install Cortex 50% faster. To install, simply drive the Cortex fastener using the included setting tool to countersink the screw to the perfect depth. Then, place your Cortex plugs on top of the fastener holes with the grains align, and tap in to finish. Collated Cortex for Trex Enhance Clamshell is made from the exact decking board, guaranteeing a perfect plug match.. Hidden fastening system for stairs, perimeter boards and more. Pre-aligned cortex plugs allow 50% faster installation. Includes 75 screws, 80 collated plug and 1 setting tool. Color Family: Brown. Decking Hardware Type: Hidden Deck Fasteners. Fastener Color: Brown. Fastener Material: Steel. Number in Package: 156. Thread Style: Coarse Thread. Square Footage Coverage per Package (sq. ft.): 25