Small diameter sizes allow for grinding in hard-to-reach places Tough, coarse aluminum oxide abrasive stays sharper longer Versatile attachment system works with any 1/4” drill or air tool Allows for quick twist-on, twist-off disc changes for lower labor costs Made in USA The National Standard Inc. abrasive Disc is a Sanding/ Grinding disc for removing paint, rust and welds in collision repair. Its small diameter makes it especially useful in hard-to-reach areas. Convenient Roloc compatible attachment securely locks the disc in place with a simple twist, and allows for disc removal just as easily. And the grades are marked on the back of the Disc for fast, accurate identification.