The ResMed H5i Cleanable Water Tub works well with both the S9 Series and the H5i series. In addition to it's easy to clean properties, the water tub is durable and stable, and on the average it lasts up to 2 years. The ResMed H5i Cleanable Water Tub is a cinch to take apart and clean. It can be disassembled effortlessly and placed in a dishwasher to clean.