Sealand Dometic 309311002 ECO Replacement Cartridge Toilet Vent Filter Improved malodorous gas filtration. Fits in same space and brackets as previous SeaLand vent filters. Fits vent hose ID sizes: 5/8 in., 3/4 in., 1 in., 1-1/2 in. One replacement cartridge fits all SeaLand ECO filter sizes. Replaces 309310004