The Pentair/Paragon THS Filter Grooved Coupling 4" Gasket is a replacement gasket used to help create a proper seal between compatible pool, spa, pump, filter, light, or equipment components. Gaskets should be replaced whenever they are flattened, cracked, swollen, brittle, or disturbed during service because reused seals can lead to leaks or poor equipment performance. Fit is extremely important, since the inside diameter, outside diameter, thickness, groove shape, and material must match the original application. This gasket is a practical choice for planned maintenance or repair work where the existing seal can no longer be trusted. Confirm the equipment model and part number B4849 before installation. Replacement sealing gasket for compatible pool or spa equipment Helps reduce leaks when installed in the correct application Recommended when the original gasket is worn, compressed, cracked, or removed during service Confirm dimensions, groove style, material, and equipment model before ordering Use part number B4849 to match the correct replacement seal