The Astral Pool lateral is designed for compatible sand filter applications where the internal collection and distribution structure needs to remain intact. A lateral is useful because it helps support the movement of filtered water through the sand bed while keeping the media where it belongs inside the tank.This 4-5/16 inch replacement is especially useful when the original lateral is cracked, broken, clogged, or worn from years of service. Replacing damaged laterals can help restore more dependable internal flow behavior and improve the overall performance of the filter.The 628 is a practical replacement for compatible Astral Pool sand filters that need renewed internal support and cleaner filtration results. Astral Pool lateral 4-5/16 inch length Designed for compatible sand filter applications Useful when the original lateral is cracked or damaged Supports cleaner and more dependable filtration performance