The EXT-NSV-B04-120 Battery Backup System Power Supply is a reliable power protection solution for the Belimo SY4–SY6 series actuators. With a maximum power of 120 W and a maximum wattage of 900 W this battery backup system ensures uninterrupted power supply for critical systems. Designed by Promation Engineering, this product is compatible with 120 V electricity and provides essential power protection for computers, networking equipment, and other electronics. The multi-function, proportional control feature makes it an ideal choice for various applications needing reliable power protection.