This standard humidifier water chamber (with a frosted tub) will last for 6-months on average with proper care and maintenance. It is compatible with all H4i Heated Humidifiers as well as HumidAire 3i (H3i) Heated Humidifiers that have been upgraded using the H4i Flip-Top Lid with Seal (Part 26953) or the H3i-to-H4i Upgrade Kit.