K4 OmniFilter O-Ring Set
The OmniFilter K4 Replacement O-rings pack contains the following four o-rings:•1 Blue K4: fits OB3, SFM2 Series A, CBF1, CBF3 Series A, OT32 Series A, RO2000, R14, CBF20 and OB1. •1 Black WC9-13: fits white-head OB5 and OCT2. •1 Black OK40: fits OB1 Series A, OB5 Series A, R12 Series A and U25 Series E. •1 Black OK30: fits CBF1 Series A, CBF3 Series B, OT32 Series B, SFM2 Series B, RO2000 Series B