for Penn-Plax Replacement Impeller For Cascade 1000 Canister Filters, Pump Accessory for Cascade 1000 Replacement Impeller Improves filter efficiency and water circulation Packing includes: 1Pcs impeller and 1pcs ceramics shaft for Penn-Plax Replacement Impeller For Cascade 1000 Canister Filters, Pump Accessory for Cascade 1000 Replacement Impeller Improves filter efficiency and water circulation Packing includes: 1Pcs impeller and 1pcs ceramics shaft