Professional contractors rely on DEWALT Self-Feed Wood-Drilling Bits when they need to bore holes 1" or larger for pipes, cables, and ductwork. Select sizes of these ultra-heavy-duty bits feature a triple-cutter design that delivers long life, minimal binding and fast chip ejection. An aggresive self-feeding screw-tip pull the bit easily through the toughest materials. Standard 7/16" Quick Change Shank allows for fast bit changes in quick change ready tools like the FLEXVOLT 60V MAX Brushless Cordless Quick-Change Stud and Joist Drill (DCD471) while preserving backward compatibility with chuck based non quick connect tools. Maximum initial battery voltage (measured without a workload) is 60 volts. Nominal voltage is 54 Set includes 1", 1-1/8", 1-1/4", 1-1/2", 1-3/4", 2-1/8" & 2-9/16" diameter bits with 5-1/2" extension.