Rejuvenate with an effervescent air spa experience EverClean system Air jets fully surrounding the bathing well Variable speed air blower with heater Acrylic with fiberglass reinforcement Ledge mounted overflow design for maximum water depth Deep Soak drain required (sold separately) Designed with undermount installation option Automatic purge with timer Pre-leveled tub bottom Complete factory installed and tested air bath system Limited Lifetime warranty including free in-home labor and parts American Standard whirlpools and air baths with EverClean incorporate a safe and effective silver-ion antimicrobial additive right into the circulation piping to protect the pipes from mold, mildew, algae and fungus that could cause deterioration or staining of the pipes.