Quite a rarity here, a mono I/O mechanical spring reverb unit in a 1u rack casing.
Controls are Level, mix (reverb level) , bass ,mid, treble Audio i/o on 1/4″ TS jacks and a1/4″ jack socket facility for a foot switch to bypass the effect.
The rear has duplicated i/o 1/4″ TS sockets, useful if racking with other gear as most 19″ equipment has rear socketing. These are not additional inputs, they are just piggy back paralleled from the front sockets.
So you can use one OR the other !
Condition is relatively poor as far as aesthetics go, doesn’t look like the manufacturer was over generous with the paint.
All i can say is go try and find/ buy another 19″ racked real spring reverb for this price.