• Manufacturer: Astral 

• Type: Replacement O-ring 

The Astral 721R1820060 pool o-ring is for the Astral 1800 Series and Cantabric 3000 Series side and top mount filters. The replacement o-ring sits between the filter body and filter lid to create a water-tight seal between the filter pieces. Damaged o-rings can be warped, cracked, or torn, which can cause air or water leaks in the filter, which can cause damage to internal components or surrounding equipment.