The Hayward tank lid with clamp ring is designed for compatible C4020, C4025, and DE4820 filter applications where the upper tank closure needs replacement. A lid with clamp ring is useful because it helps secure and seal the filter tank while still allowing access for internal service and maintenance.This replacement is especially useful when the original lid or clamp ring is cracked, leaking, damaged, or no longer securing correctly. Replacing both parts together can help restore dependable tank closure and simplify service.The DEX4820BTC is a practical service part when a compatible Hayward filter needs a lid assembly to restore dependable tank sealing and support. Hayward tank lid with clamp ring Fits compatible C4020, C4025, and DE4820 filter applications Helps restore secure tank closure and sealing Useful when the original lid or clamp ring is damaged or leaking Supports cleaner and more dependable filter service