Hayward CAT-PP2000 CAT 2000 Professional Automated Water Chemistry Controller System CAT 2000 chemical automation controller constantly monitors pH and sanitizer activity and automatically implements chemical feeding Digital, microprocessor-based design with flash technology, weatherproof membrane switch front panel interface Dry-contact outputs provided for salt-chlorine systems Simple installation, setup, operation and compatible with all types of chemical feed equipment Includes controller, sensors, machined acrylic flow cell, rotary flow sensor and PVC backboard