Controls rust-electrolysis, lime and mineral deposits, works as a sacrificial metal to protect cooler cabinet and parts with a new high efficiency tray that degrades from all sides. Safe to use and easy to install. Evaporative cooler anode kit Installs in plastic tray in water reservoir Controls rust-electrolysis, lime and mineral deposits Works as a sacrificial metal to protect cooler cabinet and parts with a new high efficiency tray that degrades from all sides Safe to use and easy to install.