AquaStar Star 18" Sq Main Drain Cover [4x9] [w Fr] [White] [VGB] (P18101) airsupply Heaters in this configuration are Heaters in this configuration are useful when the control setup already accounts for pressure monitoring elsewhere in the system and the replacement needs to match that arrangement White remains a practical choice for keeping that look bright and consistent with common shell colors This replacement is especially useful when the original cover and frame have worn together or when the existing assembly no longer provides the finished look or service confidence you want It is a practical service option when the repair calls for a larger format