The Harmsco gasket is designed for compatible BF168 and BF252 top-seal applications where a dependable seal is needed between connected filter components. A gasket is useful because it helps create a barrier against leaks, supporting cleaner installation and more dependable filter performance.This replacement is especially useful when the original gasket is flattened, cracked, brittle, worn, or leaking. Matching the correct BF168 and BF252 top-seal application helps preserve intended fit and dependable sealing support.The 635 is a practical service part when a compatible Harmsco filter needs a gasket to restore dependable top-seal performance. Harmsco gasket for BF168 and BF252 top-seal applications Helps restore dependable sealing support Useful when the original gasket is worn or leaking Designed for compatible filter applications Supports cleaner and more dependable filter performance