CobraTap™ Concrete Screws feature a constant height thread for more efficient and consistent cutting of concrete. And since it is made of high-quality forged steel; it guarantees optimal torque and maximum holding force; and is coated with Cobra Coat™ to prevent corrosion. CobraTap™ concrete screws are compatible with ACQ screws and the heads are flat or hexagonal. Concrete screws with flat head contain 1 drill bit in packs of 10 and 1 drill bit and 1 drive blade in packs of 25 and 100 units.