Backer-On Star Head Cement Board Screws are designed for a quick, secure installation of HardieBacker or equivalent fiber cement backerboard. The patented serrated head countersinks for flush seating, while the Star drive with T-25 bit provides Stikfit one-handed installation. Climacoat corrosion-resistant finish prevents rust from bleaching into grout, perfect for high-moisture areas. ANSI A108.11 compliant for cement board attachment. Installation is made easy with a standard impact or drill/driver and T-25 bit (included). Get secure results in no time with Backer-On!