New Ball Bearing Style Black & Decker Stone Holder for use with .375 Pilots. This Holder has a 5/8" Hex drive. Threads are 9/16" x 16 threads per inch.
Black & Decker Valve Seat Grinder Stone Holder Thread Adapter so you can use Sioux Stones on your Black and Decker Stone Holders. The inside threads are 9/16" x 16 tpi, and the outside threads are 11/16" x 16 tpi.