Herrmidifier 4000 is a bypass evaporative humidifier designed for forced warm-air heating systems to provide automatic humidity control. It features a 2.5-gallon per hour water consumption rate and a 1.5-gallon per hour water discharge rate. The humidifier can be mounted on either the return or supply side of the system, with the end cap always positioned so that the water connection is at the bottom. It comes with a solenoid and junction box, evaporator pad, end cap assembly, and nozzle. The humidifier operates quietly and has a self-cleaning pin to maintain optimal performance.