A new main sealing ring to fit The Aqua One Aquis 1000 and Aqua One Aquis 1200 external canister filters. The sealing ring or O Ring fits around the base of the motor unit and forms a compression seal between the top and bottom parts of the filter. Over time these become less ‘springy’ and leaks can easily occur. The old seal is easily removed and once the new one is fitted you will have at least a year of use from it with no further problems. We suggest changing the taps at the same time taking care of both common leak areas at once.