With the Dewalt DT90327-QZ Extreme bi-metal hole saw, you achieve fast and accurate 68 mm circular cutouts. This diameter is the standard size for installing drywall electrical back boxes and switch boxes. Its bi-metal design with an hss cutting edge cuts smoothly through wood, metal, and plastic with a cutting depth of up to 40 mm. The patented tooth geometry clears chips rapidly to ensure efficient and steady drilling progress. Once the cut is complete, the large continuous side slot gives you the leverage to quickly eject the core with a screwdriver, keeping your work moving without interruption.