Professional Sharpening: Designed for 315 mm drill bits, the VEVOR MR-13A drill bit sharpener with 13 elastic collets excels at sharpening the point angle and lip relief angle, quickly restoring your bits to optimal sharpness and precision. Two collet chucks are also included Adjustable Point Angle: The drill bit grinder sharpene offers a 95°135° adjustable point angle, allowing precise matching with different drilling materials and speeds for optimal performance Efficient Grinding Wheel: The CBN grinding wheel (pre-installed) is designed for high-speed steel materials, greatly improving grinding precision and efficiency