When you need to cut through plaster on walls, it gets the job done like a hot knife through butter. I had to cut holes in my plasterboard wall to blow through the insulation. I started with a semi-steel drill with a round hole, but after a few cuts the drill lost its sharpness. But this diamond duster never lost its sharpness after drilling more than 15 holes. It's all about science! It is the right tool for cutting plaster and drywall. I wish I had updated this before going through 2 semi stealth bits.