Filter Wrench 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 Filter Wrench is used to loosen acrylic housings on a RO system after it has been shut off and depressurized. $14.00 SKU: 30002 Fits standard white and clear filter housings. Does not fit the membrane housing.