IRWIN Impact Performance Series Tapcon installation bits are engineered for maximum durability and long life with impact drivers. They have a built-in hex collar stop feature for drilling the perfect hole depth for Tapcon screws, as well as other concrete screws. There's no need for the frustrating task of marking drill bits with masking tape, wrapping electrical wire around the bit, or using cumbersome stop rings to get the perfect depth ‒ once the hex collar is flush with the concrete surface, hole is the perfect depth! They're available in multiple lengths for drilling the most common hole depths for masonry fastener applications. They have a one-piece construction that withstands higher torque loads than standard quick-change bits that are built with a two-piece design. Plus, they have a black oxide finish that resists corrosion and increases the life of the bit, and a 1/4" quick-change shank that's designed to work with impact drivers, as well as reduce slipping in standard drill chucks. Tapcon is a registered trademark of Illinois Tool Works, Inc.