O-Rings for Valves on Magnum 220 and 350 Canister Filters - 4 pk by MarineLand Go to amazon.com Related posts 10 best canister filter magnum 350 for 2022 FeatureO-Rings for Valves on Magnum 220 and 350 Canister Filters - 4 pk DescriptionContains 4 O-rings.