The all-in-one HydroCore for the AprilAire 620 and 720 Humidifiers is user-friendly, popping in and out for easy maintenance and including everything needed to replace the humidifier water panel and renew key components, pre-assembled and ready to use. Emphasizing superior sustainability, the HydroCore frame is recyclable and made with recycled plastic. To maintain optimal performance and extend the lifespan of your AprilAire 620 or 720 Humidifier, replace the HydroCore annually. Made in the USA by AprilAire, a trusted leader in Indoor Air Quality solutions since 1954, the HydroCore Water Panel Cartridge is a reliable and convenient choice for helping to ensure a healthy and comfortable living environment.