This listing is for a: 

Hurricane Turning Tools Cubic Boron Nitride (CBN) Grinding Wheel 6" Diameter - 1" Wide, 0.5" Arbor - 80 Grit

Our regular price is $149.99 plus shipping ... Make an Offer !! 

More info from our website: 

We would like to introduce you to the state of the art in bench grinding, Hurricane Series, CBN plated grinding wheels. Cubic Boron Nitride (CBN) is a man-made crystalline material which is one of the hardest materials in the world. It is just slightly below Diamond on the hardness scale. CBN grinding wheels have been used in manufacturing processes for many years and are now available for common bench grinders. CBN crystals are electroplated on to a precision aluminum grinding wheel substrate resulting in the finest grinding wheels available today. CBN wheels outperform common stone wheels in many ways.
 
Features:

• Wheels are made from steel and will run smooth on all grinders
• Ideal for sharpening woodturning tools (High Speed Steel only)
• Designed for use with bench type grinders; 1800 RPM (Preferred) or 3600 RPM
• Wheel diameter does not change over time; CBN material is on the face and sides (1/4") of the wheel
• Balanced in the manufacturing process and never need "Truing" or "Dressing"
• They can make an inexpensive grinder perform almost as well as an industrial grinder