Some diving operations prefer to repack filters whenever possible from economical, bulk-purchased chemicals. Aluminum towers cannot be free-packed with chemicals without serious corrosion occurring inside the housing! Disposable cartridges are factory-sealed and should not be repacked. Global offers stainless steel canister which can be repacked indefinitely with chemicals purchased in bulk. The unit fits only Global towers #44150 and those using the Mako seal system. Includes complete instructions on the repacking process. For replacement pads, plates and shields for canister, order kit #44301. Normal Lead Time is 2-4 weeks.