The filters I received are 5/16" undersized at 4-1/2" OD. This not only shortens the life of the filter, but also causes problems in aligning the center hole of the filter with the housing. I had to work with stainless steel screws, but I won't buy again. I could not find the tolerance required by any standards organization, but the locating pins on the body are 4-11/16 inch in diameter. This gives a full 1/2 inch of travel at the top of the filter when tightening the housing. There is a risk that the filter outlet will not be properly sealed by the housing.
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