These are new and unused diamond thin rim facing wheels from Diamond Wheel, Inc.  The dimensions are 6" diameter (D) x 3/8" thick (T) x 1-1/4" hole (H).  They are 180 Grit, R100 Concentration for a little coarser finish and have ¼" width (W) and 1/16? depth (X) of diamond.  They are commonly used for sharpening the face of the carbide teeth on circle saws and should not be used on steel.