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This bypass kit fits the large 1" control valve ONLY. This will NOT fit the smaller, standard sized water softeners.
The male threads on the adapters are 1".
The center to center measurement of the inlet from the bypass to the softener is 3-3/4" - If your center to center measurement is less, you need the smaller bypass and this will not work for you.
If the top of your valve has 8 screws around the edges holding it onto the main valve body, this will work for you. If it only has 5 screws, it will NOT fit your softener. Please see images for clarification.

Water softener bypass valve assembly kit includes: High flow bypass valve assembly, four black clips, four o-rings, and two installation adapters. These parts fit in numerous water softener brands including: Whirlpool, Kenmore, EcoPure, GE, Morton, and NorthStar. Specific models listed below: Kenmore: 625.349225, 625.38208, 625.75130, 625.75190, 625.75230, 625.75290, 625.7529, 625.75390, 625.75590, 625.38376, 625.38420, 625.38426, 625.38520, 625.75480, 625.75480 Whirlpool: WHES40, WHES42, WHES44, WHES48, WHESCS, WHESFC, WHESHC General Electric (GE): GNSH45E, GXMH31H, GXSH39E, GXSH40V, GXSH45V EcoPure: EP6245, EP6260 Morton: MSD45E NorthStar: NSC30UD1, NSC40UD1, NST45ED1, NST45UD1, NST70ED1, NST70UD1