The SDU20-24B is part of Emerson's SolaHD SDU DC - B Series, a DIN Rail Uninterruptible Power Supply (UPS) designed for 24V DC applications. 

Wide operating temperature range (-20°C to +50°C).

Modular, rugged industrial-grade design with no internal fan.

Automatic self-test feature for UPS function and battery management.

Overload protection in both normal and battery modes.

User-replaceable batteries with configurable expansion options.

LED status indicators and remote monitoring capabilities.