Richmar HydraTherm Moist Heat Therapy DeviceRichmar HydraTherm Deluxe Moist Heat Therapy Device Includes Deluxe Divider Racks Optional HydraHeat Packs HydraTherm Hot Pack Heating Units for moist heat therapy feature composite polymer tanks that never rust, and are easy to maintain, needing to be cleaned only once every six months. Great for infection prevention, cleaner for your hot pack therapy, and safer for your patients! Updated Design Features Composite Polymer Tank Instead of Steel