High-precision Sharpening: MR-20G drill bits sharpener excels at sharpening point angle and lip relief angle. It features 18 elastic collets - 3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20 suitable for 3-20 diameter of drill bits. Plus, we also provide 2 drill bits collet chucks for your secure operation. Adjustable Angle: Our drill bits sharpener provides 95° to 135° point angle adjustment, ensuring precise coordination with drill hole material and rotation speed. Moreover, you can also DIY the lip relief angle through the positioner pins, grinding 4 types of lip relief angle to meet different needs. 2 Grinding Wheels, Easy Replacement: Choose between CBN or SDC grinding wheels for compatibility with various materials. The CBN model is suitable for high-speed steel materials, while the SDC model is used to grind alloy tungsten steel materials