it looks like a small u.p.s. (uninterruptable power supply).
the 9 pin d connector is usually a configuration/maintenance console port.
to be more specific, it takes a.c. in, keeps a trickle charge on a coupla batteries, and usually outputs line a.c., unless it detects the loss of the input. then it kicks in the battery backup, converting the d.c. out of the batteries to supply the a.c. outputs.
we use them on a lot of small computer systems at work.
in nomine patri, et fili, et spiritus sancti.
Meh nom eh noh...doot dooooo do do do.