12 and 24V Operation: 

The device is designed to operate on either 12 volts or 24 volts of direct current (DC) power. This allows flexibility in connecting the device to different power supply configurations commonly used in fire alarm systems.

Mounts to Single Gang Back Box: 

The device is designed to be mounted onto a single gang back box, which is a standard electrical enclosure commonly used in building infrastructure. This mounting option provides a convenient and secure installation method.

Compatible with MDL Sync Module:

The device is compatible with an MDL sync module. The MDL sync module is likely a device that provides synchronization capabilities for multiple notification appliances, ensuring they produce synchronized audio or visual signals during an alarm condition.

Mechanically and Electrically Compatible with PA400 Series Mini-Alert Sounders:

The device is mechanically and electrically compatible with the PA400 series Mini-Alert sounders. This means that the device can be used interchangeably with the PA400 series sounders without requiring significant modifications or adjustments.

Listing for Ceiling or Wall Mounting:

The device has been listed for both ceiling and wall mounting. This implies that it meets specific certification or listing requirements for installation on either a ceiling or a wall. It ensures that the device is suitable and safe for use in these mounting configurations.