The Water Sentinel ORing WSF-6 seals the filter housing to the refrigerator, and prevents water from leaking into your refrigerator compartment.
The o-ring sometimes gets damaged when the filter housing is unscrewed. The o-ring should be replaced if you can see any nicks, tears, or any other damage.
Manufacturer: WaterSentinel WSF-6
Water Sentinel WSF-6 Refrigerator O-Ring Replacement:
The Water Sentinel WSF-6 O-Ring should be lubricated every filter change and replaced every couple of filter changes or when the o-ring becomes damaged.