These BMF Zero Tolerance wheels are easy to use. When you're ready to grind hard materials like quartzite or granite, choose the right size wheel (2", 3", or 4") for your job. You can use them either wet or dry on all hard stones. If you pick a resin - filled wheel, you'll notice less vibration. For stock removal, the segmented wheels work great. Just make sure not to exceed the maximum RPM of 4,000. After use, clean the wheels to keep them in good condition. Store them in a dry place to avoid damage.