Drain Cleaning Attachment, Head Type Chain Knocker, Compatible Cleaner Series Ridgid K9-306, Connection Size 3/8 in, Maximum Drain Line Inside Diameter 3 in, Minimum Drain Line Inside Diameter 3 in, Product Type Knocker, Compatible Cleaner Manufacturer Part Number 66593, Application Pipe Wall Cleaning, Cutter Length 3 in, Cutter Type Chain Knocker, Features For Hard-Walled Pipes, For Scale, Roots, Grease and Soft Blockages, Fits Brand Ridgid, For Use With K9-306 FlexShaft(R) Machine