The MK-303 Professional 18" diamond saw blade is a continuous rim blade for lapidary materials. (Diameter 18" or 457mm; rim width is .085; arbor size is 1"; part #156729). The MK Professional diamond saw blade produces smoother cuts and is used for cutting rare and valuable materials when waste must be held to a minimum and speed of cut is essential. The Professional series diamond blades last longer and will cut faster than ordinary notched-rim or plated-diamond blades. Made in the U.S.A. Discount of 20% will be applied at the SHOPPING CART. FOB Torrance, CA or Powell, WY