For Rubbermaid® tanks only. This drain plug de-icer fits securely into the tank’s drain hole to keep the heating element away from livestock. Butterfly-shaped heating element is thermostatically controlled with over-temperature protection for safe, efficient use. Recommended for 100-300-gallon Rubbermaid tanks. Safe for horses and other livestock. 6-foot cord with durable anti-rub protector. LOCKNDRY compatible. 1500 Watts, 120 Volts, 60 Hz. cULus Listed.