TimberTech Cortex Screws For Composite - Dark Oak provide a robust hidden fastener system designed to create a clean and polished look for your composite decking. These screws are crafted from high-quality, ACQ- specialty deck screws featuring a TORX ttap drive system, ensuring long-lasting durability and reliability in a variety of outdoor settings. ly suited for stairs and perimeter boards, TimberTech Cortex Screws a secure and discreet fastening solution that preserves the sleek aesthetic of your composite deck while delivering exceptional strength and stability. Model Number: CTC100LFDO