Pentair 520588 Dummy Bypass Cell Replacement Pool/Spa Sanitizer and Automation Control Systems Dummy bypass cell replacement Fits Pentair InterlliChlor salt chlorinator sanitizers models IC60, IC40, IC20, IC15 Also fits Pentair EasyTouch pool and spa automatic control systems Pass-through cell for winter or start-up Measures 4-inch length by 4-inch height by 17-inch width