Based on this product's specifications, here are some alternatives and similar models
FF SZR-279 Automatic Transfer Switch Controller for 3 and 4-Wire Networks 24-230V AC
Summary description:
The FF SZR-279 is an automatic transfer switch controller designed for monitoring and managing power supply in 3- and 4-wire electrical networks. Operating within a voltage range of 24-230V AC, this device ensures reliable switching between primary and backup power sources. It is ideal for industrial and residential electrical systems requiring continuous power availability and automated phase monitoring.