2.25" Membrane Housing O-ring Rating: Select ratingGive it 1/5Give it 2/5Give it 3/5Give it 4/5Give it 5/5 Average: 5 (3 votes) (0 reviews) The 2.25" O-ring fits inside the horizontal membrane housing's cap to seal it. O-ring only, cap not included. $4.50 SKU: 22018 Use to seal the horizontal membrane housing