The OmniFilter K4 Replacement O-rings pack contains the following four o-rings:
Because OmniFilter has updated their housing designs, they are selling this kit with o-rings that fit the new and old systems to ensure customers get the correct o-ring for their system. This is why the K4 is listed as fitting the same housings as the OK30, for instance.
OmniFilter does not sell the K4 separately.
These o-rings come in the following dimensions:
This product was known previously as model number K4-R-02 and is now known by model number K4-M6-05.