These 1/4 in. x 3-3/4 in. hex washer head Tapper concrete screw anchors are sold as a box of 100. They are manufactured for top performance in masonry-based applications and fasten objects into concrete, brick and block. A Perma-Seal climate coating gives long-lasting protection against corrosion and the elements. They are an excellent alternative to expansion anchors, and the unique thread design allows a steady drive and torque reduction when installing in concrete. A Tapper bit is included in each package.