The RIDGID C-31 (37842) 3/8 in. x 50 ft. Inner Core Cable is ideal for cleaning 1 1/2" to 2 1/2" drain lines, including kitchen sinks, lavatory sinks, slop sinks and laundry stacks. Its inner core design provides good flexibility while resisting kinking. As torque builds, the outer spring tightens on the wire core, causing the cable to stiffen and transfer greater torque to the cutter. The cable is suitable for use with the K-3800 Drum Machine.