Product Description MK Diamond 153689 MK-303 4 by .020 by 5/8 inch - Continuous Rim is a lapidary blade. It is professional grade. The MK-303 Professional grade diamond blade has been designed for cutting rare and valuable materials when waste needs to be held to a minimum and speed of cut is essential. The MK-303 produces smoother cuts, lasts longer and cuts faster than notched rim or plated diamond blades. Designed for use with a water soluble coolant. Blades 16 inch and larger have segmented rims. From the Manufacturer MK Diamond 153689 MK-303 Professional 4-Inch diameter by .020-Inch wide by 5/8-Inch arbor diamond lapidary blade produces smoother cuts and is used for cutting rare and valuable materials when waste must be held to a minimum and speed of cuts is essential. The professional series diamond blades last longer and will cut faster than ordinary notched rim or plated diamond blades.