The Milwaukee SHOCKWAVE Impact Duty square recess insert bit is easy to use. To ensure proper compatibility, be sure to verify the proper drive size. This square recess insert bit has a #2 drive. This square recess insert bit is made of alloy steel with a finish. When shopping for a square recess insert bit, be sure your application requires fits a square recess configuration. The overall length measures 1 in. Packaged 25 pieces per package.