Cleanly knockout conduit holes with the DEWALT DCE600400D 4" Knockout Die. Punch through 10 gauge mild steel and 12 gauge stainless steel when used with the DEWALT DCE600 20V MAX* Hydraulic Knockout Tool (sold separately). The die contains embedded magnets which attach to mild steel, to maximize precision in punch alignment. The die includes laser etched markings to easily distinguish between die sizes. DeWalt DEWALT 4'' Knockout Die DCE600400D