USAutomatic 520008 Sentry 18 VAC Output Transformer, Black;

The USAutomatic transformer is a low Voltage UL approved transformer. The transformer is equipped with a DC plug for easy connection to the charge controller and can easily provide 575 cycles of operation a day without decreasing the battery charge. In the event AC power goes out the opener will operate for weeks on the battery (if cycles per day are below 20) before needing service. Accessories connected to the opener are critical. Always use solar friendly accessories to help avoid premature battery failure in cases of power outages. Transformer must not get wet.