Complete GENUINE OEM Clack WS1 Water Softener Interior Rebuild Kit with Wrench - Parts Bundle Including Service Wrench, Spacer Stack, Downflow & Regenerant Pistons. Full Service Repair Kit. COMPLETE OEM SOLUTION - Professional kit includes genuine Clack CV3005 Spacer Stack, V3011 Downflow Piston, V3174 Regenerant Piston, and V3193 Service Wrench.