The 7311127 O-ring is used on many of the larger Sears Kenmore, GE, Whirlpool, Morton, NorthStar and EcoWater softeners and filter systems. It is used on the larger 1″ bypass valve and 1″ inlet/outlet connections.
This o-ring is also listed under GE part # WS03X10072.
The o-ring is 1-1/16″ X 1-5/16″
NOTE – Some older manuals are listing this o-ring as part 7170262, which is larger (1-1/8″ X 1-3/8″). The manufacturers have used both sizes on the bypass valves and inlet/outlet connections.