The Apollo XP95 Output Unit with Isolator (55000-849) includes a loop-powered relay output and a short-circuit isolator. It does not contain any circuitry for monitoring inputs.
The Apollo XP95 Output Unit with Isolator is a Standard Interface which is designed for indoor use and is meant to be surface mounted to walls. It consists of a protective front cover, a PCB assembly and backbox with knockouts for connecting the cables.
The including short-circuit isolator senses and isolates a single short-circuit on the output loop.
