The Carrier 318518761 Humidifier Pad is a replacement evaporative element designed to support proper moisture distribution in compatible whole-house humidifier systems. Installed inside the humidifier housing, this pad absorbs water and allows air passing through the system to pick up moisture before it circulates throughout the home. It operates by providing a large evaporation surfa... https://www.hnkparts.com/318518761-reliable-parts-supplier-repl-pad-distr