Up for 'buy it now' is a General Style 3RSB Heavy Duty well made Rotary Saw Blade Set for 3" pipes, designed for cutting roots and heavy debris. Fits General and other slotted end style cables. For use with cable sizes, 1/2", 5/8" & 3/4" slotted end style cables. I have a Cable Adapter holding the bits together like they would go on your drain cleaners cable end.  The Cable Adapter holding the bits together is not for sale in this listing.