Replacement rotary knob for CX900DA filter. Made from ABS plastic, this knob is specifically designed to replace worn knobs on filtration systems, ensuring smooth operation and longer service life. Reliable and durable. Constructed from high quality materials, this knob delivers reliable performance and long life, enabling continuous operation of your filter and maintaining efficiency. Easy maintenance. Maintenance professionals and pool owners alike can rely on this easy to use rotary knob to keep filtration systems performing at their best and streamline servicing. Suitable for all pools. Indoor or outdoor pools; compatible with all pool types. Helps maintain water quality and cleanliness, contributing to a refreshing swimming experience. Use scenarios. Replacing a worn knob during routine CX900DA filter maintenance; quick field replacement by pool technicians for residential or commercial pools; suitable for indoor and outdoor pool systems to minimize downtime and maintain water quality.