The MK-303 Professional 7″ (178mm) saw blade is part number 156722. Width of the blade is .050, arbor 5/8″. The Professional saw blade by MK Diamond Products is a continuous rim blade for lapidary materials. It produces smoother cuts and is used for rare and valuable materials when waste must be held to a minimum and speed of cut is essential. These blades will cut faster and last longer than ordinary notched-rim or plated-diamond blades. Made in the U.S.A. FOB Torrance, CA.